After the battle of Thymbra, the Lydians were driven within the walls of Sardis and put to siege by the victorious Cyrus. The city fell after the 14-day Siege of Sardis, reportedly by the Lydians' failure to garrison a part of the wall that they had thought to be unsusceptible to attack because of the steepness of the adjacent declivity of the ground.

Cyrus had issued orders for Croesus to be spared, and the latter was hauled a captive before his exulting foe. Cyrus' first intentions to burn Croesus alive on a pyre were soon diverted by the impulse of mercy for a fallen foe and, according to ancient versions, by divine intervention of Apollo, who caused a well-timed rainfall. Tradition represents the two kings as reconciled thereafter; Croesus succeeded in preventing the worst rigors of a sack by representing to his captor that it was Cyrus's, not Croesus's, property being plundered by the Persian soldiery.

The kingdom of Lydia came to an end with the fall of Sardis, and its subjection was confirmed in an unsuccessful revolt in the following year that was promptly crushed by Cyrus's lieutenants.

Croesus's territory, including the Greek cities of Ionia and Aeolis, was incorporated into Cyrus' already-powerful empire. That development brought Greece and Persia into conflict and culminated in the celebrated Persian wars of Cyrus' successors. Along with acquiring Ionia and Aeolis, Cyrus also had the Egyptian soldiers, who fought on behalf of the Lydians, voluntarily surrender and join his army.