On 1 or 2 August 1537 (both dates are given in sources), near the Tuscan village of Montemurlo, the forces of the newly installed Duke Cosimo I of Florence defeated a hastily organized army of those who wished to overthrow the Medici and restore the Republic of Florence. Following the battle, Cosimo's bloody vengeance on all those who opposed Medici rule effectively ended organized opposition to his family in Florence. The victory led to the decision of Emperor Charles V to formally recognize Cosimo as Duke of Florence on 30 September 1537.
|Battle of Montemurlo|
|Part of Italian War of 1536–1538|
The Battle of Montemurlo and the Rape of Ganymede, by Battista Franco Veneziano
|Duchy of Florence (Duke Cosimo I)||Supporters of the Republic of Florence|
|Commanders and leaders|
Piero Strozzi |
700 infantry |
100 Cavalry 
- Cox-Rearick, Janet (1993). Bronzino's Chapel of Eleonora in the Palazzo Vecchio. Berkeley: Univ. of California Press. pp. 303–04. ISBN 978-0-520-07480-4.
- Littel, Eliakim (1880). The Living Age, Vol. 144. Boston, Massachusetts: Littel & Co. p. 588.
- Villari, Pasquale (1911). . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 18 (11th ed.). Cambridge University Press. pp. 31–41, see page 36, middle of fourth para.
'On the evening of the 31st of July Vitelli marched towards Prato with seven hundred picked infantry and a band of one hundred horse, and on the way fell in with other Spanish foot soldiers who joined the expedition.
- Young, Colonel G. F. (1930). The Medici. [Whitefish, MT]: Kessinger Publications. p. 553. ISBN 978-1-4191-8129-0. Retrieved 7 December 2011.
1st August 1537
- Bull, translated by George (1965). The lives of the artists; a selection (Repr. ed.). Baltimore: Penguin Books. pp. 266. ISBN 978-0-14-044460-5.
2 August 1537
- Davies, Jonathan (2009). Culture and power : Tuscany and its universities 1537-1609 ([Online-Ausg.]. ed.). Leiden: Brill. p. 31. ISBN 978-90-04-17255-5.
- Spini, Georgio (1980). Cosimo I e l'indipendenza del Principato Mediceo (in Italian). Florence, Italy: Vallecchi Ed. pp. 84–91.