How did a family of bankers turn Florence into the capital of art?

A family of bankers did it, by paying for it. In the 1400s the Medici ran the largest bank in Europe, and Cosimo de' Medici, who became the unofficial head of the Florentine Republic in 1434, spent a fortune on art, buildings and books. Florence was already a capital of textiles, and the wealth that trade brought meant big projects could be commissioned and people had leisure for study. Historians list several reasons the Renaissance began there, among them Florence's political structure, the Medici's patronage and the arrival of Greek scholars, so the Medici are one ingredient in the story, not all of it.

The Medici began in cloth, through Florence's wool guild, and founded their bank in Florence under Giovanni di Bicci de' Medici. It held far more Church money than capital of its own: in 1427 the Rome branch held about 100,000 florins on deposit from the papal court, while the whole bank's capital was only about 25,000 gold florins.

Cosimo ruled without a crown. Florence's councils resisted him and even sent him into exile in 1433, and he was back the next year. He enjoyed spending: he said that for fifty years he had done nothing but earn money and spend it, and that spending gave him more pleasure. Over his life he spent more than 600,000 gold florins on art and culture, backing Donatello (whose David was a Medici commission), Fra Angelico and Fra Filippo Lippi. He had grown up with three books, owned 70 by thirty, and in 1444 opened the first public library in Florence, at San Marco, a hub for the humanists.

The Medici were not alone: the Visconti and Sforza, the Este, the Borgia and Della Rovere and the Gonzaga also inspired the Italian Renaissance. And the money did not last: Lorenzo the Magnificent neglected the bank, which led to its ruin, and it fell in 1494.