 Complete the following phrase:  The main challengers of the Albizzi family were the Medicis, first under Giovanni de Medici, later under his son Cosimo de Medici. The Medici controlled the Medici bankthen Europes largest bankand an array of other enterprises in Florence and elsewhere. In 1433, the Albizzi managed to have Cosimo exiled. The next year, however, saw a pro-Medici Signoria elected and Cosimo returned. The Medici became the towns leading family, a position they would hold for the next three centuries. Florence organized the trade routes for commodities between England and the Netherlands, France, and Italy. By the middle of the century, the city had become the banking capital of Europe, and thereby obtained vast riches. In 1439, Byzantine Emperor John VIII Palaiologos attended a 