When Cyrus came to the throne of Persia in 559 BC, his kingdom was restricted to a small area of south-east Iran. He may have extended his power over the important city of Susa, which led to an attack by king Astyges of Media (north-west Iran). Cyrus defeated him and extended Persian control from eastern Iran to the Halys River in Anatolia.

Croesus, king of Lydia (western Anatolia) felt threatened by the expanding Persian empire and his forces clashed with the Persian army. The battle ended in a draw and both armies withdrew for the winter. The Persian forces, however, pursued the Lydian army and besieged the capital Sardis for two weeks before it fell.

In 539 BC Cyrus invaded Babylonia. The Persian army met the Babylonian forces at Opis, east of the River Tigris and defeated them. Cyrus now controlled much of the Near East from the frontier of Egypt, through Anatolia and Iran. He founded a new royal centre in his homeland, Parsagadae (city of the Persians).

Later Cyrus turned his attention to Iran and Central Asia and it was while campaigning here that he was killed in 530 BC.