Brunelleschi's Dome of Florence Cathedral

On August 7, 1420, construction began on the dome of Florence's cathedral, designed by architect Filippo Brunellschi. An excerpt from the article:

"In 1418 the Opera del Duomo announced a public competition for the construction of the dome with a handsome prize of 200 gold florins—and a shot at eternal fame—for the winner. Leading architects of the time flocked to Florence to present their ideas.

After many uncertainty the Opera del Duomo agreed to make Filippo Brunelleschi the superintendent of the cupola project and appointed Lorenzo Ghiberti, Brunelleschi’s fellow goldsmith, as a co-superintendent. The two men had been rivals since 1401, when they had vied for another illustrious commission, the new bronze doors for the Florentine Baptistery. Ghiberti had won. Now Brunelleschi, whose design for the cupola had been accepted outright, was forced to work side by side with his gallingly successful rival.

The construction of the Dome began on 7 August 1420."