During the 10th and 11th centuries Amalfi was estimated to have a population of 50,000–70,000 people. It rose to become an economic powerhouse, a commercial center whose merchants dominated Mediterranean and Italian trade in IX and X century, before being surpassed and superseded by the other maritime republics of the North, like Pisa, Venice, and Genoa. In 1073, Amalfi lost its independence, falling to Norman invasion and subsequently to Pisa in 1137.