Battle of Potidaea The Battle of Potidaea was , with the Battle of Sybota , one of the catalysts for the Peloponnesian War . It was fought near Potidaea in 432 BC between Athens and a combined army from Corinth and Potidaea , along with their various allies . Potidaea was a colony of Corinth on the Chalcidice peninsula , but was a member of the Delian League and paid tribute to Athens . After Sybota , Athens demanded that Potidaea pull down part of its walls , expel Corinthian ambassadors , and send hostages to Athens . Athens was afraid that Potidaea would revolt due to Corinthian or Macedonian influence , as Perdiccas II of Macedon was encouraging revolts among Athens ' other allies in Thrace . Athens gathered a fleet of 30 ships and 1 , 000 hoplite s under the overall command of Archestratus , which was originally meant to fight Perdiccas in Macedonia but was diverted to Potidaea . The Potidaeans sent ambassadors to Athens and Sparta , and when negotiations broke down in Athens , Sparta promised to help Potidaea revolt . The Athenian fleet sailed for Potidaea , but when it arrived , Archestratus attacked the Macedonians instead , as the Potidaeans had already revolted and allied with Perdiccas . Corinth sent 1 , 600 hoplites and 400 light troops to Potidaea as well , under the command of Aristeus . In response , Athens sent out another 2 , 000 hoplites and 40 more ships , under the command of Callias . After some fighting against Perdiccas , the combined Athenian forces sailed to Potidaea and landed there . Perdiccas and 200 of his cavalry joined with Aristeus , and their combined army marched to Potidaea as well . In the ensuing battle , Aristeus ' wing of Corinthian troops defeated a section of the Athenian line , but elsewhere the Athenians were victorious . Aristeus returned to Potidaea along the seacoast with some difficulty , hoping to avoid the main Athenian army . A reserve force of Potidaeans , located in nearby Olynthus , attempted to relieve Aristeus , but they were defeated as well . The Corinthians and Potidaeans lost about 300 men , and the Athenians about 150 , including Callias . The Macedonian cavalry did not join the battle . The Athenians remained outside Potidaea for some time , and were reinforced by another 1 , 600 hoplites under the command of Phormio . Both sides built walls and counter - walls , and the Athenians succeeded in cutting off Potidaea from the sea with a naval blockade . During the blockade , representatives from Athens and Sparta met in Sparta , resulting in a formal declaration of war . However , this siege , which lasted until 430 / 429 , seriously depleted the Athenian treasury , dumping as much as 1 , 000 talents / year into this attack . This made the Athenian people unhappy , and in combination with the plague that swept through Athens in the early 420s BC , made the continued leadership of Pericles untenable . The Periclean strategy of hiding behind the Long Walls and relying on the low cash reserves of the Peloponnesians was starting to become unfavorable to the greater Athenian consciousness . In several of Plato ' s dialogues , the philosopher Socrates is revealed to be a veteran of the Battle of Potidaea , where he saved the life of Alcibiades ( " Symposium " 219e - 221b ) .