The Palazzo Vecchio is the town hall of Florence. It was originally called the Palazzo della Signoria, after the Signoria of Florence, who were the ruling body of the Republic of Florence. It has served as government seat for numerous leaders, including the Duke of Athens. From 1540 to 1550 it was the home of Cosimo I de' Medici, who also enlarged the palace.
The name was officially changed after Cosimo moved to the Pitti Palace, renaming his former palace the Palazzo Vecchio, the "Old Palace", although the adjacent town square, the Piazza della Signoria, still bears the old name. He also moved the seat of government to the Uffizi. Although much of the Palazzo Vecchio is now a museum, it remains the symbol of local government, and still houses the office of the mayor of Florence.
The building is attributed to Arnolfo di Cambio who began constructing it in 1299, incorporating the ancient tower of the Foraboschi into its facade. It is the result of three successive building stages between the 13th-16th centuries, the actual construction of Arnolfo's palace, overlooking the square and placed next to the Loggia dei Lanzi. After the death of Arnolfo in 1302, the palace was finished by other artists in 1314. The solid cubicle shaped building is enhanced by the simple tower with its Lederle clock.
The First Courtyard was remodelled in 1470 by Michelozzo. The second courtyard contains the massive pillars built in 1494 to sustain the great "Salone dei Cinquecento" on the second floor. The third courtyard was used mainly for offices of the city. Between the first and second courtyard the massive and monumental stairs by Vasari lead up to the "Salone dei Cinquecento".
The "Salone dei Cinquecento" was built in 1494 by Simone del Pollaiuolo. Later, under Cosimo I, the Hall was enlarged by Vasari. During this transformation famous works were lost inlcuding the "battle of Cascina" by Michelangelo, and the "battle of Anghiari" by Leonardo.