History

Florence was founded as a Roman colony in 59 BCE; its medieval rebirth began in 1115 when the commune gained independence from the Margrave of Tuscany. The wealth that funded the great buildings came from the wool trade and banking: Florentine merchants and bankers introduced the letter of credit to Europe and coined the gold florin in 1252, the most widely used currency on the continent for three centuries. The Medici family assumed control of the Florentine Republic in 1434 under Cosimo de' Medici; their patronage over the next century made Florence the capital of European intellectual and artistic life. Lorenzo the Magnificent (1469–1492) hosted the Platonic Academy and commissioned works from Botticelli, Leonardo da Vinci, and the young Michelangelo at his household.

The Duomo's dome was the central engineering problem of the age. The octagonal crossing was 42 metres wide with no precedent in the medieval tradition for closing a span that large without a wooden centring form. Brunelleschi solved it by building two self-supporting shells in herringbone brick, each ring of bricks capable of bearing the weight of the next before mortar set. The outer shell follows the pointed profile that reduces horizontal thrust; the inner shell carries the lantern that Brunelleschi designed but never saw finished (he died in 1446; the lantern was set in 1461). The drum galleries, the marble inlay of the exterior, and the interior fresco cycle by Vasari and Zuccari (1572–1579) completed the cathedral's external appearance as it stands today.