PRIME MINISTER

also called premier the head of the executive branch of government in countries with a parliamentary system. The prime minister serves under the chief of state (even if the chief of state has only titular or ceremonial powers), except in those rare cases in which the chief of state assumes the functions of prime minister. Although the origin of the title lies in 17th-century France, where the Cardinal de Richelieu was acknowledged in 1624 as principal or premier ministre, it was in England that the office of the prime minister definitively evolved as that of the chief executive of the government in a parliamentary context.