437 BCE

Pericles, concerned for Athenian trade with Greek settlements to the East, and in order to counteract a new and possibly threatening Thracian–Scythian alliance, leads Athens' fleet to Pontus on the Black Sea and establishes friendly relations with the Greek cities of the region. Mnesikles starts to build Propylaia, Acropolis, Athens. The work is canceled in 432 BC, due to the Peloponnesian War, and thus is never finished.

In the 430s BC, the 5th century BC.