Perdiccas II of Macedon
Perdiccas II was king of Macedonia from about 454 BC to about 413 BC. He was the son of Alexander I. After the death of Alexander in 452, Macedonia began to fall apart. Macedonian tribes became almost completely autonomous, and were only loosely allied to the king. By 434, Perdiccas' brother, Philip, had challenged Pediccas for the throne, snd enlisted the support of Athens and king Derdas of Elimea. Perdiccas responded by stirring up rebellion in a nmber of Athenian tribute cities, including Potidaea. Athens responded with force, and sent 1000 hoplites and 30 ships to Macedonia where they captured Therme. They went on to besiege Pydna, where they were met by reinforcements of a further 2000 hoplites and 40 ships. However, as the Athenians were besieging Pydna, they received news that Corinth had sent a force of 1600 hoplites and 400 light troops to support Poteidaia. In order to combat this new threat, Athens made an alliance with Perdiccas, and proceeded to Poteidaia. Perdiccas immediately broke the treaty and marched to Poteidaia, where the Athenians were victorious.
In 431, Athens entered into an alliance with the Thracians, after Nymphodorus, an Athenian, married King Sitalkes’ sister. Nymphodorus then negotiated an agreement between Athens and Perdiccas, where Perdiccas regained Therme. As a result of this, Athens withdrew her support for Philip, and the Thracians promised to assist Perdiccas in capturing him. In return, Perdiccas marched on the Chalcidians, the people he had originally persuaded to revolt.
However, Perdiccas once again betrayed the Athenians and sent 1000 troops to support a Spartan assault on Acarnania in 429 but they arrived too late to help. (Thucydides 2.80) In response to this, Sitalkes invaded Macedonia with the promise of support from Athens. This support never materialized, and Perdiccas once again used diplomacy to ensure the survival of Macedonia. He promised the hand of his sister in marriage to the nephew of Sitalces, who then persuaded Sitalces to leave.
After this altercation, Perdiccas was allied to the Spartans and, in 424, helped helped the Spartan Brasidas to take Amphipolis from the Athenians, one of her most important colonies, mainly for its ready access to timber for her fleets. This was a severe blow to Athens, and would tie them to Macedonian timber for years to come, which strengthened Macedonia’s bargaining power considerably. In return for this, the Spartans helped Perdiccas secure his borders, by leading an assault on king Arrhabaeus of Lyncus, with the promise of support from the Illyrians. However, the Illyrians switched sides and attacked Perdiccas and his Spartan allies. The poorly trained Macedonian troops fled, and so the Spartans also retreated and attacked the Macedonian baggage train in anger. (Thucydides 4.128) This soured relations between Macedonia and the Peloponnese for years to come, and pushed Perdiccas closer to Athens, allying himself with them in 423/2.
By 417, Perdiccas had left the Athenians and joined the Spartan-Argive alliance. Just four years later, bowing to Athenian pressure, Perdiccas broke with the Peloponnese, and aided Athens in their attack on Amphipolis.