Year 405 BC was a year of the pre-Julian Roman calendar.
Events
By place
Greece
The Athenian fleet follows the Spartan admiral, Lysander, to the Hellespont. The Athenian fleet is destroyed in the Battle of Aegospotami. The Spartan king Pausanias lays siege to Athens. Lysander's fleet blockades Piraeus. This starves Athens. Theramenes tries to negotiate with Lysander. He is away for three months.
Sicily
Dionysius the Elder rises to power as the tyrant of Syracuse. He makes peace with the Carthaginian general. Carthage is in control of most of Sicily. Dionysius the Elder expands his power. He builds a wall around Syracuse. The Greek citizens of Naxos, Catana, and Leontini are removed from their cities. Many of them are made slaves.
By topic
Drama
Aristophanes' play The Frogs is performed. Euripides' The Bacchae and Iphigeneia at Aulis are performed at the Dionysia and win first prize.
Art
The Erechtheum, which includes The Porch of Maidens (Caryatid Porch), is completed in the Ionian style on the Acropolis in Athens after 16 years of building.
Deaths
Philolaus, Greek mathematician and philosopher (approximate date) (b. c. 480 BC)