Darius became ruler of the empire of the Medes and Persians in 522 BC. He had two capital cities, Ecbatana and Susa (as in the Book of Esther).
This official cylinder seal made with agate was discovered in Egypt, was used for rolling an impression on clay tablets. The seal shows the king hunting a lion from his chariot, inscribed, "Darius the great king", in Old Persian, Elamite and Babylonian cuneiform, the three official languages of the Persian empire. Ezra chapters 5-6 describe that the governor of Jerusalem wrote to Darius in 520 BC, about building the wall of Jerusalem, and received a reply.
British Museum Link