Many Greek settlements on the mainland relied on trade with each other to get needed goods. Some had enough farmland to meet their own needs, so they were less dependent on trade.
Most goods were carried on ships owned by merchants. These ships were built of wood, with large rectangular cloth sails. Merchants had ships built, not for speed, but for space to hold goods. Because these ships traveled only about three to five miles per hour, journeys were long. A one-way trip from the mainland could take two months.
The Greeks traded among the city-states, with Greek colonies, and in the wider Mediterranean region. Olive oil and pottery from the mainland were exchanged for such goods as grain, timber, and metal.