In historical times, colonists from Megara (c. 667 BC) founded Byzantium, as well as Chalcedon and, in Sicily, Hyblaean Megara, a small polis north of Syracuse. The most famous citizen of Megara in antiquity was Euclid, but the 6th century poet Theognis also came from Megara.
In the Peloponnesian War, (c. 431 BC-404 BC) Megara was an ally of Sparta.
Today, Megara is a suburb of Athens, and is home to 10,000 people, especially the municipality. Distance is 42 km WNW of Athens, and is linked by a federal or state freeway connecting the Peloponnese, Western Greece, and Athens. It will now by linked by a high-speed rail line. The neighboring city to the east is Neos Peramos, and Kakia Skala to its west.