History

Begun in May 1533 under the supervision of Alessandro Vitelli and Pier Francesco da Viterbo, the fortress was constructed by da Viterbo and Antonio da Sangallo the Younger between 1534 and 1537 on orders from Alessandro de’ Medici. The first stone was laid on 15 July 1534; by December that year, the fortification was largely complete.

The structure served multiple purposes: controlling the city after the Medici’s return from the Siege of Florence, accommodating troops, and providing refuge for rulers during potential revolts. Its massive form deliberately intimidated the Florentine population. The side facing the city received monumental treatment from Sangallo to amplify this effect.

During the Lorraine period, additional buildings of architectural interest were constructed, including officers’ quarters and a theater. When Florence’s fourteenth-century walls were demolished during the capital period, the fortress remained; its moats were subsequently leveled and most walls buried.

The military maintained control until 1967. Restoration and adaptation work for Firenze Fiera began in recent decades, exposing archaeological features and requiring demolition of barracks-era structures.