Restoration of the Athenian democracy (405–403 BC)
Pausanias' first known command was in Autumn 405, when he led the main force of the Peloponnesian League to besiege Athens, although Agis was already in Attica, at the head of the garrison of Decelea, a stronghold occupied by Sparta since 415. Perhaps Pausanias refused to let Agis command the army because of the century-long enmity between the kings. Athens nevertheless refused to submit and Pausanias returned to Sparta with the army. The Peloponnesian War ended the following year after Lysander negotiated the Athenian surrender, notably with Theramenes, and installed a pro-Spartan oligarchy, known as the Thirty Tyrants, as he had done in Athens' former allied cities when he captured them. This regime was rapidly challenged by the Athenian democratic resistance led by Thrasybulus, who captured the Piraeus harbour in 403; the Thirty then retreated to the city of Eleusis in western Attica. Sparta initially made a loan of 100 talents to the Thirty (to hire mercenaries), while Lysander went to Eleusis and his brother Libys as navarch blockaded Piraeus.
Whereas the crushing of the Athenian democrats appeared imminent, Pausanias brought a drastic change in Sparta. In July 403, he convinced a majority of three ephors (out of five) and Agis II to lead the Peloponnesian army to Attica to put Lysander in check. Only one ephor's name is known: Nausikleidas, who also followed Pausanias in Attica. Pausanias initially disguised his real intentions and commanded the army with the official purpose of helping the Thirty. Thebans and Corinthians consequently refused to join his expedition, as they believed he was going to make Athens a Spartan possession. Once in Attica, Pausanias relieved Lysander from his command, then fought a small battle against the Athenian Democrats commanded by Thrasybulus. Soon after, Pausanias opened negotiations with the Democrats and advised them to send an official embassy to Sparta. After they heard the Athenian ambassadors, the Spartan ekklesia and the ephors sent a 15-man commission to Attica in order to assist Pausanias to conclude a settlement. Pausanias therefore applied his plan: he granted Athens full internal autonomy, restored the democracy, removed the Spartan garrison from Athens, pronounced a general amnesty among Athenians, while Athens joined the Peloponnesian League. This settlement completely overturned Lysander's policy since the end of the Peloponnesian War, since Lysander's oligarchies in the other Greek cities were probably removed at the same time. Out of gratitude for Pausanias, the Athenians built a large monument for the Spartans who died in the earlier skirmishes against the Democrats. It was located on the Sacred Way, just outside the Dipylon.
The main source for the events, Xenophon, tells that Pausanias acted against Lysander because he was jealous of his power. However, Pausanias was probably more concerned by the growing anger expressed by Sparta's allies against Lysander's aggressive imperialism, and wanted instead to return to Sparta's traditional foreign policy of isolationism abroad and conservatism at home. Lysander and his friends, such as Gylippus, also brought some of wealth they had amassed during the war against Athens, which provoked resentment in Sparta, likely led by Pausanias.
