Old Iranian leaders, also known as shahs (5 letters), were the rulers of the Persian Empire from the Achaemenid dynasty in 550 BCE to the Pahlavi dynasty in 1979. They were responsible for the expansion of the empire and the development of its culture, art, and architecture. The most famous shah was Cyrus the Great, who founded the Achaemenid dynasty and is credited with creating the first charter of human rights. Other notable shahs include Darius I, Xerxes I, and Reza Shah Pahlavi.