The Battle of Thymbra is the decisive battle in the war between Croesus of the Lydian Empire and Cyrus the Great.

Cyrus, having pursued Croesus into Lydia following the drawn Battle of Pteria, meets the remains of Croesus' partly disbanded army in battle on the plain north of Sardis in December, 547 BC.

Even though Croesus' army is reinforced with many new men, Cyrus utterly defeats it, despite being outnumbered more or less 2:1.

This proves decisive, and after the 14 day Siege of Sardis, the city and possibly its king falls, and Lydia is conquered by the Persians.