Peace of Nicias
The Dipylon gate was built, along with the neighbouring Sacred Gate, in 478 BC as part of Themistocles' fortification of Athens following the Persian Wars. The new circuit was much wider than the old one that was destroyed by the Persians, and many of the graves and monuments of the already existing Kerameikos cemetery were used in its construction, a fact which earned Themistocles the hostility of many Athenians whose relatives' tombs were despoiled. During the Peace of Nicias (421–416 BC), the wall was complemented by a moat and a secondary wall ("proteichisma"). The construction of the Pompeion in the empty space between the Dipylon and Sacred Gate began shortly after, but was not completed until the next century. The Themistoclean Wall was torn down after the Athenian defeat in the Peloponnesian War in 404 BC, but in 394 BC, with the help of Persian funds, the Athenian statesman Conon restored it.