The Sienese Ghibellines, supported by the forces of King Manfred of Sicily, defeat the Florentine Guelphs at Montaperti.

The River Arno flooding causing massive damage in Florence as recorded by the Florentine chronicler Giovanni Villani.

The bishop of Florence blesses the first foundation stone for the new ''campanile'' (bell tower) of the Florence Cathedral, designed by the artist Giotto di Bondone.

Construction of the dome of Santa Maria del Fiore begins in Florence.

The Family de' Medici were expelled from Florence.

The bonfire of the vanities occurs in which supporters of Girolamo Savonarola burn thousands of objects like cosmetics, art, and books in Florence, Italy.

Girolamo Savonarola is burned at the stake in Florence, Italy, on the orders of Pope Alexander VI.

Michelangelo's ''David'' is unveiled in Florence.

The Florentines drive out the Medici for a second time and Florence re-establishes itself as a republic.

After 18 months of siege, Siena surrenders to the Florentine-Imperial army. The Republic of Siena is incorporated into the Grand Duchy of Tuscany.

Jacopo Peri's ''Euridice'', the earliest surviving opera, receives its première performance in Florence, signifying the beginning of the Baroque Period

Two-thirds of Florence, Italy is submerged as the River Arno floods; together with the contemporaneous flood of the Po River in northern Italy, this leads to 113 deaths, 30,000 made homeless, and the destruction of numerous Renaissance artworks and books.