Year 387 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Tribunate of Papirius, Fidenas, Mamercinus, Lanatus and Poplicola. The denomination 387 BC for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.
Events
By place
Greece
Antalcidas, commander of the Spartan navy, actively assists Persia against Athens. After escaping from the Athenian blockade at Abydos, he attacks and defeats a small Athenian force, then joins his fleet with a supporting fleet sent from Syracuse. With this force, which is soon further augmented with ships supplied by the Persian satraps of the region, he sails to the Hellespont, where he is in a position to cut offthe trade routes that bring grain to Athens.
The Persians, unnerved by some of Athens' actions, including supporting King Evagoras of Cyprus and PharaohHakor of Egypt, decide that their policy of weakening Sparta by supporting its enemies is no longer wise. So Antalcidas enters into negotiations with the Persian satrapTiribazus and reaches an agreement under which the Persians will enter into the war on the Spartan side if the allies refuse to make peace.
With Antalcidas' Spartan fleet in control of the Hellespont, Sparta deprives Athens of her Bosporus trade and tolls. The Athenians, mindful of being in a similarly serious situation as when defeated in the Peloponnesian War less than two decades before and facing Persian intervention on Sparta's side, are thereby ready to make peace.
With the support of the Persian KingArtaxerxes II, King Agesilaus II of Sparta concludes "the King's Peace" with Greek allied forces in a manner favourable to Sparta. Under the Peace, all the Asiatic mainland and Cyprus remain under Persian control, Lemnos, Imbros, and Scyros remain Athenian dependencies, and all the other Greek states are to receive autonomy. By the King's Peace, the Persians become key players in Greek politics.
Plato is forced by Dionysius to leave Syracuse after having exercised the right of free speech too broadly. Plato returns to Athens, outside which he founds a school.
Roman Republic
Rome begins to rebuild after being invaded by the Gauls under Brennus.