The Medici ruled Florence at the high point of the Renaissance. Their power derived from their bank. The Church condemned usury as a sin and made it illegal, so the Medici made their bank indispensable to the church. They avoided taxation by running the city themselves, completely subverting its claims to being democratic. The bank finally collapsed in 1494, but for five generations the Medici had dominated Renaissance Italy. They were to shape attitudes to morals and money in the modern world. This is their fascinating and often bloody story.