Megara was a coastal city-state. Megara was highly respected in the ancient Greek world. Megara was similar to Corinth. They people were ruled by a king. They had their own coinage. They had public work programs to keep people employed. Megara had beautiful statues and open air arenas for plays. Their boys went to school. Their girls learned at home.
Like Corinth, there was a great deal of freedom in Megara. You could move there from another city-state and rent a home, or even buy one.
Like all the Greek city-states, Megarians loved to establish new towns. They were great sailors. They sailed around the Mediterranean, trading with other Greek city-states, and looking for places to establish new outposts. One of the town they founded was on the coast of Turkey. They named it Byzantium. After a while, Byzantium changed its name to Constantinople. Constantinople was renamed Istanbul, which is a very famous city in modern day Turkey.
Megarians, like all the Greeks, were trained warriors. Spartans might be the best warriors, but all Greek citizens knew how to fight. Megarians would fight if they had to, but they would much rather trade or negotiate. In the ancient Greek world, Megara was famous for its textiles. Everybody wanted their richly colored and beautifully designed fabrics. Sometimes they could talk their way out of trouble simply by trading their glorious textiles.