In 1418, when construction of the Florence Cathedral's apse had been almost completed, a competition was announced for the erection of the dome; it was won, among criticism and some confusion, by Filippo Brunelleschi. He erected his revolutionary structure between 1420 and 1436, first adding to the beauty of the church's proportions by constructing a tambour 15 m high at the base of the ovoid-shaped dome, which was designed in such a way as to avoid the need for reinforcement or scaffolding. The dome has double walls: between the inside wall and the roof outside are the stairs by which one ascends to the lantern at the top. The dome is 113 m high including the lantern and has a diameter of 44 m.
View the ground plan and section of the dome.