Gyges died in battle c.652, fighting against the Cimmerians, and was succeeded by Ardys. The most successful king was Alyattes, under whom Lydia reached its peak of power and prosperity. Croesus was defeated by Cyrus the Great at the battles of Pteria and Thymbra. Cyrus annexed Lydia after the Siege of Sardis which ended in early 546 BC, but the fate of Croesus himself is uncertain.