Peace of Nicias
Brasidas died in 422 BC, the year Athens and Sparta struck an accord, the Peace of Nicias, that freed Macedonia from its obligations as an Athenian ally. Following the 418BC Battle of Mantinea, the victorious Spartans formed an alliance with Argos, a military pact PerdiccasII was keen to join given the threat of Spartan allies remaining in Chalcidice. When Argos suddenly switched sides as a pro-Athenian democracy, the Athenian navy was able to form a blockade against Macedonian seaports and invade Chalcidice in 417BC. PerdiccasII sued for peace in 414BC, forming an alliance with Athens that was continued by his son and successor ArchelausI (). Athens then provided naval support to ArchelausI in the 410BC Macedonian siege of Pydna, in exchange for timber and naval equipment.