The site is believed to have been continuously inhabited as a city since at least the end of the 8th century BC. It became a municipium allied to Rome at the end of the 3rd century BC. The city was a bishop's residence in the 5th century, and its episcopal power was affirmed during the 12th century. With the decline of the episcopate, Volterra became a place of interest of the Florentines, whose forces conquered Volterra. Florentine rule was not always popular, and opposition occasionally broke into rebellion. These rebellions were put down by Florence.
When the Florentine Republic fell in 1530, Volterra came under the control of the Medici family and later followed the history of the Grand Duchy of Tuscany.