Ḵosrow I (531-579 CE), Sasanian king, son of Kawād I, was considered as the ideal king throughout Islamic times as the “just” (ʿādel) king, and he certainly was one of the main protagonists of Late Antiquity. According to Arthur Christensen’s historiographic view, Ḵosrow inaugurated the most brilliant period of Sasanian Iran, through a series of important economic, fiscal, administrative, religious and military reforms, whose global effects probably escape to us. This entry illustrates his life and times according to the extant sources.