IRAN, HISTORY OF

history of the Iranian Plateau from prehistoric times to the present. The article covers as well the succession of ancient empires centred there, the borders of which extended beyond those of the present country. The early history of Iran may be divided into three phases: (1) the prehistoric period beginning with the earliest evidence of man on the Iranian Plateau (c. 100,000 BC) and ending roughly at the start of the 1st millennium BC; (2) the protohistoric period covering approximately the first half of the 1st millennium BC; and (3) the period of the Achaemenid dynasty (6th to 4th century BC), when Iran entered the full light of written history. The civilization of Elam, centred off the plateau in lowland Khuzestan, is an exception, for written history began there as early as it did in neighbouring Mesopotamia (c. 3000 BC). The sources for the prehistoric period are entirely archaeological. Early excavation in Iran was limited to a few sites. In the 1930s archaeological exploration increased rapidly, but work was abruptly halted by the outbreak of World War II. After the war ended, interest in Iranian archaeology revived quickly, and since 1950 numerous excavations have revolutionized the study of prehistoric Iran. For the protohistoric period the historian is still forced to rely primarily on archaeological evidence, but much information comes from written sources as well. None of these sources, however, is both local to and contemporary with the events described. Some sources are contemporary but belong to neighbouring civilizations that are only tangentially involved in events in the Iranian Plateau; for example, the Assyrian and Babylonian cuneiform records from lowland Mesopotamia. Some are local but not contemporary, such as the traditional Iranian legends and tales that supposedly speak of events in the early 1st millennium BC. And some are neither contemporary nor local but are nevertheless valuable in reconstructing events in the protohistoric period (e.g., the 5th-century-BC Greek historian Herodotus). For the study of centuries of the Achaemenid dynasty there is sufficient documentary material, so that this period is the earliest for which archaeology is not the primary source of data. Economic texts from Mesopotamia, Elam, and Iran; historical inscriptions such as that of Darius the Great at Bisitun; contemporary and later classical authors; and later Iranian legends and literature contribute, among other sources, to the understanding of the Achaemenid period. For a discussion of the religions of ancient Iran, see Iranian religion. For a discussion of visual arts from the prehistoric period through the Sasanian period, see Iranian arts. For a detailed account of Mesopotamian history through the Sasanian period, see Mesopotamia, history of. Additional reading General works The Cambridge History of Iran (1968 ) contains extensively documented studies from the beginning to the Safavid period in the six volumes already published. Essays in volumes of The Cambridge Ancient History (1923 ) also examine particular periods. Single-volume works include Percy Sykes, A History of Persia, 3rd ed., 2 vol. (1930, reissued 1969); Roman Ghirshman, Iran from the Earliest Times to the Islamic Conquest (1954, reissued 1978); Alessandro Bausani, The Persians: From the Earliest Days to the Twentieth Century (1971, originally published in Italian, 1962); Richard N. Frye, The Heritage of Persia, 2nd ed. (1976), and The History of Ancient Iran (1984); and Donald N. Wilber, Iran: Past and Present: From Monarchy to Islamic Republic, 9th ed. (1981). Dynastic tables and essays on different aspects of Iranian history and culture may be found in A.J. Arberry (ed.), The Legacy of Persia (1953, reissued 1968). Prehistory L. Vanden Berghe, Archologie de l'Iran ancien (1959, reissued 1966), is a fairly complete survey by province and period of Iranian archaeology for all periods to the Sasanian, with a good bibliography. Although written as a guide-book, Sylvia A. Matheson, Persia: An Archaeological Guide, 2nd ed., rev. (1976), contains much detailed information on monuments dating from 6000 BC to the 13th century and on archaeological finds up to 1970. Frank Hole (ed.), The Archaeology of Western Iran: Settlement and Society from Prehistory to the Islamic Conquest (1987), is written for a reader with some previous knowledge of the history and archaeology of the area; the last chapter provides a useful summary and overview of developments. The Elamites, Medians, and Achaemenids George G. Cameron, History of Early Iran (1936, reissued 1976); and William Cullican, The Medes and Persians (1965), are good general surveys. Muhammad A. Dandamaev and Vladimir G. Lukonin, The Culture and Social Institutions of Ancient Iran (1989), includes a section on prehistory up to the 6th century BC but concentrates on the Achaemenid period. A.R. Burn, Persia and the Greeks: The Defence of the West, c. 546478 B.C., 2nd ed. (1984), provides a fairly balanced view of the Achaemenids in their dealings with the Greeks. A.T. Olmstead, History of the Persian Empire: Achaemenid Period (1948, reissued 1978); and J.M. Cook, The Persian Empire (1983), are good introductions. The Hellenistic and Parthian periods Franz Altheim, Weltgeschichte Asiens im griechischen Zeitalter, 2 vol. (194748), is a brilliant study of Hellenism in the Orient with particular attention to the role of the Iranians. Franz Altheim and Ruth Stiehl, Geschichte Mittelasiens im Altertum (1970), includes two chapters in English. Other works include Neilson C. Debevoise, A Political History of Parthia (1938, reissued 1969); and W.W. Tarn, The Greeks in Bactria & India, 3rd ed. by Frank Lee Holt (1985). K.H. Ziegler, Die Beziehungen zwischen Rom und dem Partherreich (1964), is a valuable work with a bias toward Rome. The Sasanian period The History of al-Tabari (1985 ), provides a translation and commentary of the essential work by at-Tabari (c. 859923). Georgina Herrmann, The Iranian Revival (1977), examines Parthian and Sasanian antiquities and history. Arthur Christensen, L'Iran sous les Sassanides, 2nd ed., rev. (1944, reissued 1971), is the only comprehensive one-volume history. Iran from 640 to the present Modern research has produced articles on Iran in P.M. Holt, Ann K.S. Lambton, and Bernard Lewis (eds.), The Cambridge History of Islam, 2 vol. (1970, reissued in 4 vol. 1980). An essential reference work is The Encyclopaedia of Islam, 4 vol. and suppl. (191338); a new ed. is in progress (1960 ). W. Barthold (V.V. Bartold), Turkestan Down to the Mongol Invasion, 4th ed. (1977; originally published in Russian, 2 vol., 18981900), is the essential survey of northeastern Iranian history from about AD 600 to the 13th century. Iran under Arab governors in the 7th9th centuries is explored in Richard N. Frye, The Golden Age of Persia: The Arabs in the East (1975). M.A. Shaban, The 'Abbasid Revolution (1970), concentrates on the Arab conquest and settlement of Khorasan. Discussions of various ruling dynasties of the period between the end of the 'Abbasid empire and the rise of the Seljuqs may be found in C.E. Bosworth, The Ghaznavids: The Empire in Afghanistan and Eastern Iran, 994 : 1040, 2nd ed. (1973), and The Later Ghaznavids: Splendour and Decay (1977); and Roy P. Mottahedeh, Loyalty and Leadership in an Early Islamic Society (1980), on the Buyids, their subjects, and their social structure. The Seljuqs and Mongols are the subjects of Ann K.S. Lambton, Continuity and Change in Medieval Persia: Aspects of Administrative, Economic, and Social History, 11th14th Century (1988); and David Morgan, The Mongols (1986), and Medieval Persia, 10401797 (1988), which covers up to the Qajar period.Roger Savory, Iran Under the Safavids (1980), surveys the rise and fall of the Safavid dynasty. Laurence Lockhart, The Fall of the Safavi Dynasty and the Afghan Occupation of Persia (1958), and Nadir Shah (1938, reissued 1973), deal with the period 16941747. The brief Zand dynasty is examined by John R. Perry, Karim Khan Zand: A History of Iran, 17471779 (1979). Studies of the Qajars may be found in Firuz Kazemzadeh, Russia and Britain in Persia, 18641914: A Study in Imperialism (1968); Ann K.S. Lambton, Qajar Persia: Eleven Studies (1987), a collection of previously published essays on agriculture and commerce in 19th-century Iran; and C.E. Bosworth and Carole Hillenbrand (eds.), Qajar Iran: Political, Social, and Cultural Change, 18001925 (1983). Hamid Algar, Religion and State in Iran, 17851906: The Role of the Ulama in the Qajar Period (1969, reissued 1980); and Mangol Bayat, Mysticism and Dissent: Socioreligious Thought in Qajar Iran (1982), discuss 19th-century religious development. Peter Avery, Modern Iran (1965), is a general work on the 19th and 20th centuries to 1963. M. Reza Ghods, Iran in the Twentieth Century: A Political History (1989); Edward G. Browne The Persian Revolution of 19051909 (1910, reissued 1966); and Amin Banani, The Modernization of Iran, 19211941 (1961), are also useful. Works on the period of the Pahlavi dynasty include L.P. Elwell-sutton, Modern Iran (1941); Joseph M. Upton, The History of Modern Iran: An Interpretation (1960, reprinted 1970); George Lenczowski (ed.), Iran Under the Pahlavis (1978); Ervand Abrahamian, Iran Between Two Revolutions (1982), covering 1905 to 1979; and Fakhreddin Azimi, Iran: The Crisis of Democracy (1989), discussing the years from the end of Reza Shah's reign to the overthrow of the Mosaddeq government, 194153.The political and socioeconomic background of the Islamic revolution is explored by Robert Graham, Iran: The Illusion of Power, rev. ed. (1980); Nikki R. Keddie, Roots of Revolution: An Interpretive History of Modern Iran (1981); Haleh Afshar (ed.), Iran: A Revolution in Turmoil (1985), a collection of essays by Iranian historians and social scientists; Mohsen M. Milani, The Making of Iran's Islamic Revolution: From Monarchy to Islamic Republic (1988); Mohammed Amjad, Iran: From Royal Dictatorship to Theocracy (1989); and Misagh Parsa, Social Origins of the Iranian Revolution (1989). Information on the religious background of the revolution can be found in Said Amir Arjomand, The Shadow of God and the Hidden Imam: Religion, Political Order, and Societal Change in Shi'ite Iran from the Beginning to 1890 (1984); Nikke R. Keddie (ed.), Religion and Politics in Iran: Shi'ism from Quietism to Revolution (1983); Roy Mottahedeh, The Mantle of the Prophet: Religion and Politics in Iran (1985), on the place of religion in 20th-century Iran, set in a historical context; Shahrough Akhavi, Religion and Politics in Contemporary Iran: Clergy-State Relations in the Pahlavi Period (1980); and Michael M.J. Fischer, Iran: From Religious Dispute to Revolution (1980). The Islamic republic itself is the subject of Sepehr Zabih, Iran Since the Revolution (1982); Shaul Bakhash, The Reign of the Ayatollahs: Iran and the Islamic Revolution, rev. ed. (1990); Robin Wright, Sacred Rage: The Crusade of Modern Islam, rev. ed. (1986), and In the Name of God: The Khomeini Decade (1989), both works recounting Iran's efforts to export its revolution to other Islamic countries; and R.K. Ramazani, Revolutionary Iran: Challenge and Response in the Middle East (1986)a later printing (1988) included a new epilogue on the Iranian-American arms deal. The war in the Persian Gulf between Iran and Iraq is analyzed by several pre-armistice works, Shahram Chubin and Charles Tripp, Iran and Iraq at War (1988); Majid Khadduri, The Gulf War: The Origins and Implications of the Iraq-Iran Conflict (1988); and Edgar O'ballance, The Gulf War (1988), a narrative of military operations; and by several post-armistice publications, Hanns W. Maull and Otto Pick (eds.), The Gulf War: Regional and International Dimensions (1989); and Efraim Karsh (ed.), The Iran-Iraq War: Impact and Implications (1989). The Editors of the Encyclopdia Britannica Iran from 640 to the present The advent of Islam (640829) The Arab invasion of Iran made a break with the past that affected not only Iran but all of western Asia and resulted in the assimilation of peoples who shaped and vitalized Muslim culture. (See also Islamic world.) The Prophet Muhammad had made Medina, his adopted city, and Mecca, his birthplace, centres of an Arabian movement that Muslim Arabs developed into a world movement by the conquest of Iranian and Byzantine territories. Neither the Iranian nor the Byzantine empire had been unfamiliar to those Arabs who were the former's Lakhmid and the latter's Ghassanid vassals, the two empires' frontier guardians against fellow Arabs who roamed deeper in the Arabian Desert. Also, Meccan and Medinese Arabs had established commercial connections with the Byzantines and Sasanids. The immunity of Mecca's ancient sanctuary against outlawry and outrage had promoted this city's commercial importance. The Ka'bah, as the sanctuary was called, was cleansed of idols by Muhammad, who had himself once been engaged in commerce. He made it the sanctuary of a monotheistic faith whose sacred writings were impregnated with the injunctions and prohibitions needed by a business community for secure and stable trading. Arab tribalism beyond urban fringes was less easily broken than idols. It was embedded in the desert sparsity that led to warfare and careful counting of a tribe's male offspring. After Mecca and Medina had become Muslim, to secure the routes they depended upon necessitated winning the desert Arabs' allegiance. In the process of doing this, wars over water holes, scanty pastures, men-at-arms, and camels were enlarged into international campaigns of expansion. The vulnerability of Sasanid Iran assisted the expansionist process. In AD 623 the Byzantine emperor Heraclius reversed Persian successes over Roman arms, namely, the capture of Jerusalem in 614 and a victory at Chalcedon in 617. His victim, Khosrow Parviz, died in 628 and left Iran a prey to a succession of puppet rulers who were frequently deposed by a combination of nobles and Zoroastrian clergy. Thus, when Yazdegerd III, Iran's last Sasanid and Zoroastrian sovereign, came to the throne in 632, the year of Muhammad's death, he inherited an empire weakened by Byzantine wars and internal dissension. The former Arab vassals on the empire's southwestern border realized that their moment had arrived, but their raids into Sasanid territory were quickly taken up by Muhammad's caliphs, or deputies, at MedinaAbu Bakr and 'Umar (632634; 634644)to become a Muslim, Pan-Arab attack on Iran. An Arab victory at al-Qadisiyya in 636/637 was followed by the sack of the Sasanid winter capital at Ctesiphon on the Tigris. The Battle of Nahavand in 642 completed the Sasanids' vanquishment. Yazdegerd fled to the empire's northeastern outpost, Merv, whose marzban, or march lord, Mahuyeh, was soured by Yazdegerd's imperious and expensive demands. Mahuyeh turned against his emperor and defeated him with the help of Hephthalites from Badghis. The Hephthalites, an independent border power, had troubled the Sasanids since at least 590, when they had sided with Bahram Chubin, Khosrow Parviz's rebel general. A miller near Merv murdered the fugitive Yazdegerd for his purse. The Sasanid end was ignominious, but it was not the end of Iran. Rather, it marked a new beginning. Within two centuries, Iranian civilization was revived with a cultural amalgam, with patterns of art and thought, with attitudes and a sophistication that were indebted to its pre-Islamic Iranian heritagea heritage changed but also stirred into fresh life by the Arab-Muslim conquest. Abu Muslim's revolution Less time was needed before the Arabs' assimilation with Iranians in regions they colonized caused a new Islamic beginning, Abu Muslim's movement, which began in Khorasan, in 747. This revolution followed years of conspiracy directed from Medina and across to Khorasan along the trade route that linked the Far East to Merv and thence with the West. Along the route merchants with contacts in the Mesopotamian Arab garrison cities of Kufah, Wasit, and Basra acted as intermediaries. Iranians who by converting to Islam had become clients, or mawali, of Arab patrons played direct and indirect parts in the revolutionary movement. The movement also involved Arabs who had partnered Khorasanian and Transoxanian Iranians in ventures in the great eastwest trade and intercity trade of northeastern Iran. The revolution was, nevertheless, primarily an Arabo-Islamic movement, aimed to supplant a militaristic, tyrannical central government whose fiscal problems made it avid for revenue by one more sympathetic to the needs of the merchants of eastern Islam. Abu Muslim, a revolutionary of unknown origin, was able in Merv to exploit the discontent of the merchant classes as well as that of the Arab and Iranian settlers. The object of attack was the Umayyad government in Damascus. When Muhammad died in 632, his newly established community in Medina and Mecca needed a guiding counsellor, an imam, to lead them in prayers and an amir almu'minin, Commander of the Faithful, to ensure proper application of the Prophet's divinely inspired precepts. As the Prophet, Muhammad could never be entirely succeeded, but it was accepted that men who had sufficient dignity and who had known him could fulfil the functions, as his caliphs (khulafa'), or deputies, and imams. After Abu Bakr and 'Umar, 'Uthman was chosen for this role. By 'Uthman's time, factionalism was growing among Arabs, partly the result of the jealousies and rivalries consequent upon acquiring new territories, and partly the result of the competition between first arrivals in them and those who followed. There was also uncertainty over the most desirable kind of imamate. One faction, the Shi'ah, supported 'Ali, the Prophet's cousin and husband of his favourite daughter, Fatimah, for the caliphate, since he had been an intimate of Mu hammad and seemed more capable than the other candidates of expressing Muhammad's wisdom and virtue as the people's judge. The desire for such a successor points to disenchantment with 'Uthman's attempt to strengthen the central government and impose demands on the colonies. His murder in 656 left his Umayyad relatives poised to avenge it, while 'Ali was raised to the caliphate. A group of his supporters, the Kharijites, desired more freedom than 'Ali was willing to grant, with a return to the simplest interpretation of the Prophet's revelation in the Qur'an, along puritanical lines. A Kharijite killed 'Ali in 661. The Shi'ah thenceforth crystallized into the obverse position of the Kharijites, emphasizing 'Ali's relationship to the Prophet as a means of making him and his descendants by Fatimah the sole legitimate heirs to the Prophet, some of whose spiritual power was even believed to have been transmitted to them. This Shi'ism centuries later became the official Islamic sect of Iran. In the interim, Shi'ism was a rallying point for socially and politically discontented elements within the Muslim community. In addition to the Kharijites, another minority sect was thus formed, hostile from the beginning to the Umayyad government that seized power on 'Ali's death. The majority of Muslims avoided both the Shi'ite and Kharijite positions but followed instead the sunnah, or tradition, as these orthodox believers conceived the Prophet to have left it and as Abu Bakr, 'Umar, 'Uthman, and 'Ali, too, the rightly guided first caliphs, had observed and codified it. Abu Muslim's revolutionary movement was as much as anything representing Medinese mercantile interests in the Hejaz, dissatisfied with Umayyad inability to shelter Middle Eastern trade under a Pax Islamica. To promote the revolution aimed to destroy Umayyad power, the movement exploited Shi'ite aspirations and other forces of disenchantment. The Kharijites were excluded, since their movement opposed the idea of a caliphate of the kind Abu Muslim's adherents were fighting to establishone that could command sufficient respect to hold together an Islamic universal state. A discontented element ready to Abu Muslim's hand in Khorasan, however, was not a religious grouping but Arab settlers and Iranian cultivators who were burdened by taxation. In Iran, the first Arab conquerors had concluded treaties with local Iranian magnates who had assumed authority when the Sasanid imperial government disintegrated. These notablesthe marzbans and landlords (dehqans)undertook to continue tax collection on behalf of the new Muslim power. The advent of Arab colonizers, who preferred to cultivate the land rather than campaign farther into Asia, produced a further complication. Once the Arabs had settled in Iranian lands, they were required to pay the kharaj, or land tax, collected by Iranian notables and their agents under treaty with the Muslim government. The Iranian collectors proved extortionate and aroused the hostility of both Arab and Persian. Another source of discontent was the head tax, or jizyah, which was applied to non-Muslims of the tolerated religionsJudaism, Christianity, and Zoroastrianism. Thus, on conversion to Islam, Iranians expected exemption from this degrading tax. But the Umayyad government, burdened with imperial expenses, often refused exemption to the Iranian converts. The tax demands of the Damascus government were as distasteful to those urbanized Arabs and Iranians in commerce as they were to those in agriculture; and hopes of easier conditions under the new rulers than under the Sasanids were not fully realized. The Umayyads ignored Iranian agricultural conditions, which required constant reinvestment to maintain irrigation works and to halt the encroachment of the desert. This no doubt made the tax burden, from which no returns were visible, all the more odious. Furthermore, the regime failed to maintain the peace so necessary to trade. Damascus feared the breaking away of remote provinces where the Arab colonists were becoming assimilated with the local populations. The government, therefore, deliberately encouraged tribal factionalism in order to prevent a united opposition against it. Thus the revolution set out to establish an Islamic oecumene above divisions and sectarianism, the Pax Islamica already referred to, which commerce required and which Iranian merchants without status in the Sasanid social hierarchy looked to Islam to provide. Ease of communication from the Oxus to the Mediterranean was wanted but without what seemed like a nest of robbers calling themselves a government straddling the route at Damascus. In 750 Umayyad power was destroyed and the revolution gave the caliphate to the 'Abbasids (see Islamic world and Iraq, history of: The 'Abbasid Caliphate). Hejazi commercial interests had in a sense overcome the military party among leading Muslim Arabs. Greater concern for the East was manifested by the new caliphate's choice of Baghdad as its capital, situated on the Tigris a short distance north of Ctesiphon and designed as a new city, to be free of the factions of the old Umayyad garrison cities of Kufah, Wasit, and Basra. The Hellenistic and Parthian periods Alexander and his successors Between 336 and 330 BC Alexander completed the conquest of the whole Achaemenid Empire. (For the story of the conquest see Alexander The Great and ancient Greek civilization: Alexander the Great.) Alexander's burning of the royal palace at Persepolis in 330 symbolized the passing of the old order and the introduction of Greek civilization into western Asia. Greek and Macedonian soldiers settled in large numbers in Mesopotamia and Iran. Alexander encouraged intermarriage and fostered Greek culture, but he also retained a large part of the Achaemenid administrative structure and introduced Oriental elements and Greek political institutions. Alexander left no heir. His death in 323 BC signalled the beginning of a period of prolonged internecine warfare among the Macedonian generals for control of his enormous empire. By the end of the 4th century BC Seleucus I Nicator had consolidated his control over that part of Alexander's territory that had corresponded to the Achaemenid Empire. Seleucus, who, with his son Antiochus I, assumed supreme power, established a government with two capitals: Antioch on the Orontes River in Syria and Seleucia on the Tigris River in Babylonia. The greatest part of Asiafrom the Aegean to the Punjabbelonged to this vast kingdom, and to its diverse and varied populace must be added several allied Greek cities, both in Greece and in Asia Minor. (See also Mesopotamia, history of: Mesopotamia from c. 320 BC to c. AD 620.) The nobles and the nomads As he was finishing the conquest of eastern Iranand at a moment when his attention was being drawn toward the conquest of IndiaAlexander was confronted by two human factors that were of the greatest importance for the future of his empire. The first of these was the powerful local aristocracy of this part of the Achaemenid Empire, an aristocracy that held enormous properties and dominated the indigenous population; the second was the nomad population that for centuries had wandered along the northern and northeastern frontiers of Iran. Alexander seems to have admired greatly the barons of eastern Iran; he had taken note of their ardour during the two years of hard and constant fighting in his conquest of northeastern Iran. Realizing how such a force could benefit the future of his empire, Alexander convoked an assembly of Bactrian nobles. He ordered 30,000 young men to be chosen for training in the Macedonian military disciplines. He understood the importance and effectiveness of the Iranian light cavalry armed with the bow, and his army would make use of this training in its march toward the plains of India. And finally, Alexander married Roxana of Sogdiana, daughter of a chief of one of the conquered countries, thereby symbolizing the union of the two races. But Alexander was not unaware that other measures were needed to ensure his control of these vast territories. He founded many new cities, or refounded some that were already in existence. Many of these were placed strategically along the northern frontiers as protection. Almost half of these new cities were located in the high (eastern) satrapies. This policy of Alexander was soon abandoned by the Seleucids, whose efforts at city planning were mostly confined to their western possessions. In contrast with Alexander, the Seleucids were unable to maintain the good rapport with the eastern Iranian nobility that Alexander had believed essential. And this deficiency, a result of the Seleucids' pro-Macedonian policies, was one of the principal causes for the progressive decline of the Seleucid Empire. The second of the human factors was the nomads who inhabited the immense territories beyond the northern frontiers. They fought constantly with the settled populations, but could nevertheless occasionally ally with them in the face of necessity. When Alexander arrived on the banks of the Jaxartes River, it marked the limit of the civilized world; beyond stretched the Eurasian wilderness. The Roman historian Quintus Curtius recounts Alexander's meeting with a delegation of Scythians who gave him a warning. They told him, These words sum up what the nomad world represented to an empire that stretched several thousand miles from east to west. The non-nomad population knew the threat only too well. Alexander was not the first to cross swords with the nomads. Cyrus, founder of the Achaemenid Empire, had paid with his life while fighting them; and Darius, believing he could take them from behind through southern Russia, suffered a crushing defeat in his campaign against the Scythians along the shores of the Black Sea. If the nomads and the eastern Iranian nobility were the two dominant factors in the decline of the Seleucid kingdom, and if the events they provoked were some of the principal causes for the exhaustion and eventual fall of that state, these same causes played a not inconsiderable role in the collapse of Parthian power. This power was undermined by an aristocracy that retained its military power and refused to bend before the royal will or to give up its meddling in the country's politics. In the meantime, the kingdom's unruly neighbours to the north and the northeast, at the cost of the lives of several Parthian sovereigns, weakened the kingdom and sometimes added a complementary element to the often numerous intrigues of the pretenders to supreme power during the course of the almost half a millennium of the existence of the Parthian kingdom. The Sasanian period Foundation of the empire Rise of Ardashir I At the beginning of the 3rd century AD, the Arsacid Empire had been in existence for some 400 years. Its strength had been undermined, however, by repeated Roman invasions, and the empire became once more divided, this time between Vologases V (209222), who seems to have ruled at Ctesiphon, on the left bank of the middle Tigris in what is now Iraq, and Artabanus V (c. AD 213224), who was in control of Iran and whose authority at Susa, in southwestern Iran, is attested by an inscription of AD 215. (See also Mesopotamia, history of: The Sasanian period.) It was against Artabanus V that a challenger arose in Persis. Ardashir I, son of Papak and a descendant of Sasan, was the ruler of one of the several small states into which Persia had gradually been divided. His father had taken possession of the city and district of Istakhr (Estakhr), which had replaced the old residence city of Persepolis, a mass of ruins after its destruction by Alexander the Great in 330 BC. Papak was succeeded by his eldest son, who was soon killed in an accident, and in AD 208 Ardashir replaced his brother. He first built for himself a stronghold at Gur, called after its founder Ardashir-Khwarrah (Ardashir's Glory), now Firuzabad, southeast of Shiraz in Fars. He subdued the neighbouring rulers and disposed, in the process, of his own remaining brothers. His seizure of such areas as Kerman, Esfahan, Elymais, and Characene (Mesene), to the east, north, and west of Fars, respectively, led to war with Artabanus, his suzerain. The conflict between the two rivals lasted several years, during which time the Parthian forces were defeated in three battles. In the last of these, the battle in the plain of Hormizdagan (AD 224), Artabanus was killed. There is evidence to support the assumption that Ardashir's rise to power suffered several setbacks. Thus, Vologases V struck coins at Seleucia on the Tigris as late as AD 228/229 (the Seleucid year 539). Another Parthian prince, Artavasdes, a son of Artabanus V, known from coins on which he is portrayed with the distinguishing feature of a forked beard, seems to have exercised practical independence even after AD 228. Numismatic evidence further reflects the stages of Ardashir's struggle for undisputed leadership. He appears on his coins with four different types of crown: as king of Fars, as claimant to the throne before the battle at Hormizdagan, and as emperor with two distinctly different crowns. It has been suggested that this evidence points to two separate coronation ceremonies of Ardashir as sovereign ruler, the second, perhaps, indicating that he may have lost the throne temporarily. According to at-Tabari, the Arabic historian (9th10th centuries), Ardashir, after having secured his position as a ruler in western Iran, embarked on an extensive military campaign in the east (AD 227) and conquered Seistan (Sakastan), Gorgan (Hyrcania), Merv (Margiana), Balkh (Bactria), and Khwarezm (Chorasmia). The inference that this campaign resulted in the defeat of the powerful Kushan Empire is supported by the further statement of at-Tabari that the king of the Kushans was among the eastern sovereigns, such as the rulers of Turan (Quzdar, south of modern Quetta) and of Mokran (Makran), whose surrender was received by Ardashir. These military and political successes were further extended by Ardashir by his taking possession of the palace at Ctesiphon, by his assuming the title king of kings of the Iranians, and by his refounding and rebuilding of the city of Seleucia, located on the Tigris River, under the new name of Weh-Ardashir, the Good Deed of Ardashir. The chronology of events in the early Sasanian period was calculated by the German orientalist T. Nldeke in 1879, and his system of dating is still generally accepted. The discovery of fresh evidence in manuscript materials dealing with the life of Mani, a religious leader whose activities fall in the early Sasanian period, led to a reassessment of Nldeke's calculations by W.B. Henning, by which the principal events are dated about two years earlier. Another alternative was proposed by S.H. Taqizadeh, who preferred a sequence by which the same events are placed about six months later than the dates established by Nldeke. Since the dating systems employed by the Sasanians themselves were based on the regnal years of the individual kings, whose exact coronation dates are often subject to dispute, several details remain uncertain, and their definite solution has not been possible. A firmer basis of calculation is obtained when the ancient sources quote dates in terms of the Seleucid era, either according to the computation that prevailed in Babylonia, which started from 311 BC, or after the Syrian reckoning, beginning in 312 BC. Tables 2 and 3 give the dates of events of the early Sasanian period as they can be established on direct numismatic or literary evidence in the differing chronological systems of Nldeke, Henning, and Taqizadeh. The Sasanian Empire at the time of Shapur I. Wars of Shapur I Shortly before his death, probably because of failing health, Ardashir abdicated the throne in favour of his chosen heir, his son Shapur I. The latter assumed the responsibilities of government but delayed his coronation until after his father's death. Coins thus exist showing Ardashir together with his son as heir apparent and Shapur alone wearing the eagle cap, indicating the exercise of royal rule before his coronationbesides the normal series of Shapur crowned as king. Shortly after his accession, Shapur was faced with an invasion of Persia by the emperor Gordian III (238244): Several years later, in AD 256 (or AD 252), another confrontation between the Persians and Romans occurred: including Antioch, the capital of Syria, itself. A third encounter took place when the emperor Valerian (253260) came to the rescue of the city of Edessa, in Syria, which was besieged by the Persian army: The source for these quotations is Shapur's own account of the events. It was unknown until 1938, when expeditions of the Oriental Institute in Chicago discovered a long inscription on the walls of an Achaemenid building known as the Ka'be-ye Zardusht (Ka'ba of Zarathushtra). The text is in three languages, Sasanian Pahlavi (Middle Persian), Parthian, and Greek. Besides the narrative of the military operations, the inscription provides a description of the Persian Empire of the time and an inventory of Zoroastrian religious foundations established by Shapur I to commemorate his victorious wars. These foundations were fire temples dedicated to the soul (memory) of the founder himself, of members of the royal family, and of prominent officials who had served under Shapur and his predecessor. The list of the officials who are specified by the positions they held throw light on the administrative organization of the empire. The Sasanian Empire at the time of Shapur I.