n. 25B6; verb
Robert II reigned for nineteen years : BE KING/QUEEN, be monarch, be sovereign, sit on the throne, wear the crown, rule.
chaos reigned : PREVAIL, exist, be present, be the case, occur, be prevalent, be current, be rife, be rampant, be the order of the day, be in force, be in effect; formal obtain.
25B6; noun
during Henry's reign : RULE, sovereignty, monarchy.
his reign as manager : PERIOD IN OFFICE, incumbency, managership, leadership.