Renaissance Figures Cosimo de' Medici, also known as Cosimo the Elder, lived from 1389--1464. He was the first Medici to rule Florence. He was exiled from Florence in 1433, but he returned in 1434 and doubled his wealth through banking. He ended Florence's traditional alliance with Venice and supported the Sforza family in Milan. His historical significance was being a patron to such artists as Brunelleschi, Donatello, and Ghiberti, and as the founder of the Medici Library. ?