The battle of Sardis (395 BC) was a minor victory for Agesilaus II of Sparta during his period in command of the Spartan war effort in Asia Minor that triggered the fall of the Persian satrap Tissaphernes and led to a six month truce in Caria and Lydia (Persian-Spartan War).
Agesilaus arrived in Asia Minor in 396 and based himself at Ephesus. He was faced by two Persian satraps - Tissaphernes, rules of Caria and Lydia, with a base at Sardis, and Pharnabazus, satrap of Phrygia. In 396 he tricked them both, making public preparations for a campaign against Tissaphernes in Caria before turning north to raid Pharnabazus's lands. In 395 he reversed the trick. This time he made public preparations for a campaign against Sardis, north-east of Ephesus. Tissaphernes assumed that this was a bluff, and prepared to face another invasion of Caria. The road north was thus undefended when Agesilaus led his army north to attack Sardis.
We have two rather different accounts of the campaign itself. According to Xenophon the Greeks were able to reach the Plain of Sardis without facing any opposition and were able to pillage the local area for three days. Tissaphernes rushed north to defend Sardis. He led part of his army into the city, but left his cavalry commander outside the city. This man ordered the baggage train to camp west of the Pactolus River, which flows north past the western side of Sardis. He then sent the Persian cavalry to attack the Spartan looters. Agesilaus was nearby with most of his army, and took advantage of this mistake. He sent his cavalry to pin down the Persians, followed by his light peltasts, and then the hoplites from the youngest ten age classes. The rest of the army followed behind. The Persian cavalry fell for the trap, and fought the Greek cavalry. The Greek infantry then began to arrive and the Persians gave way. Some of the Persians were killed while attempting to cross the Pactolus, while the rest escaped. The Greeks then captured the baggage camp.
The Oxyrhynchus Historian provides a different account, although with the same basic result. In this version the Greeks were harassed by archers as they advanced into the plains west of Sardis. Tissaphernes followed close behind, using his light troops and cavalry to harass the Greeks. Agesilaus marched with his hoplites in a hollow square, with the baggage train protected inside it. Fighting is reported at a river, which might be the same battle recording by Xenophon. Agesilaus set an ambush for Tissaphernes, leaving 1,400 men hidden in a grove. They surprised the troops harassing the Greek army, and forced them into flight. Agesilaus then sent his cavalry and light troops to pursue the defeated Persians, before capturing the baggage camp. The Persians lost 600 dead in this fighting.
In either case the battle ended with Tissaphernes discredited and his baggage train lost. Artaxerxes decided to depose of him, and sent his vizier Tithraustes to replace him. Tissaphernes was executed, and Tithraustes offered fresh peace terms. Earlier the Persians had demanded that the Spartans leave Asia Minor without offering concessions. Now they offered to give the Greek cities of Asia autonomy in return for a tribute. Agesilaus agreed to a six month truce in Tithraustes's provinces while the Spartan government considered the offer. This didn't entirely halt the fighting, as the truce didn't apply to the provinces ruled by Pharnabazus.