Croesus was the king of Lydia from 560/561 B.C. until his defeat by the Persians in about 547 B.C..
Croesus was friendlier to the Greeks than his father had been, giving refuge at one point to the Athenian statesman Solon.
Croesus' uneasy relations with the Greeks obscures the larger fact that he was their last bastion of the Ionian Greeks against the increasing Persian power in Anatolia. Croesus allied himself with Amasis II of Egypt and Nabonidus of Babylonia, while preparing a campaign against Cyrus the Great of Persia in 547 B.C.. Before starting his campaign he turned to Delphi oracle to inquire about the fate of his campaign. The Pythia answered, with typical ambiguity: "If Croesus crossed the Halys, a great empire shall be brought down"–one of the most famous oracular statements from Delphi.
Croesus, now feeling secure, launched his campaign into the Persian Empire. He was intercepted near the Halys River in central Anatolia and an inconclusive battle was fought. As was usual in those days, the armies would disband for winter and Croesus did accordingly. Cyrus did not and he attacked Croesus in Sardis, capturing him. It became clear that the powerful empire Croesus was about to destroy was his own.
The reasons for his death still remain unconvincing. Herodotus claims that he was saved from a burning pyre by Cyrus after a omen from the god Apollo. His death is is traditionally dated 546 B.C., after Cyrus' conquest. However, from what can by found from what little has been found from Cyrus' records In the Nabonidus Chronicle, it is said that Cyrus "marched against the country Lydia, killed its king (Croesus), took his possessions, put there a garrison of his own." However, it should be noted that the cuneiform word that is thought to represent "Lydia" is damaged, and its interpretation is doubtful.