阴土鸡年 (female Earth-Rooster) −304 or −685 or −1457 — to — 阳金狗年 (male Iron-Dog) −303 or −684 or −1456
Year431 BC was a year of thepre-Julian Roman calendar. At the time, to Romans it was known as theYear of the Consulship of Cincinnatus and Mento (or, less frequently,year 323Ab urbe condita). The denomination 431 BC for this year has been used since the early medieval period, when theAnno Dominicalendar era became the prevalent method in Europe for naming years.
Athens enters into an alliance with King Sitalkes ofThrace, after Nymphodorus, an influential Athenian, marries Sitalkes' sister. Nymphodorus then negotiates an agreement between Athens andMacedon's KingPerdiccas II, through which Perdiccas regainsTherma. As a result, Athens withdraws its support for Perdiccas' brother, Philip, and the Thracians promise to assist Perdiccas in capturing him. In return, Perdiccas marches on theChalcidians, the people he has originally persuaded to revolt.
ATheban raid onPlataea, the only pro-Athenian city inBoeotia, is a failure and the Plataeans take 180 prisoners and put them to death. Athens supports Plataea while Sparta aligns itself with Thebes. Sparta enlists the help of the Greek cities inItaly andSicily. Both Sparta and Athens appeal toPersia, but without result.
The Spartans, led by KingArchidamus II, invadeAttica effectively starting thefirst phase of the Peloponnesian War, actually the second of such wars, between the Athens-ledDelian League and the Sparta-ledPeloponnesian League. The Spartans lay waste to the countryside around Athens. Athenian leader,Pericles, does not seriously oppose them, rather withdrawing the rural population of the country districts within Athens' city walls. Instead, he pursues active naval warfare and reduces any danger from the island ofAegina by replacing its native population with Athenians.
The Athenian fleet raids thePeloponnese and pilages the area aroundMethone. The town is saved through an intervention by the Spartan generalBrasidas. The Athenians then sail on laying waste to the coastal areas of the western Peloponnese.
TheGreekphilosopherEmpedocles distinguishes thefour elements - earth, fire, water, and air - that he claims all substances are made of. He explains the development of the universe by the forces of attraction and repulsion known as Love and Strife.
Phidias returns toAthens, where he is imprisoned (for having been portrayed on the shield of the statue of thegoddess Athena) and dies before the trial.
