Greek colonies were settlements established by the ancient Greeks outside their homeland, primarily during the 8th to 6th centuries BCE. These colonies were founded for various reasons, including overpopulation, the search for arable land, and trade opportunities. They spread across the Mediterranean and the Black Sea, leading to the establishment of cities like Marseille in France and Syracuse in Sicily. The colonies maintained cultural ties to Greece, sharing language, religion, and customs. They often operated independently but remained connected to their mother cities, known as metropoleis. This expansion played a crucial role in the spread of Greek culture and influence throughout the ancient world.