Arezzo is best known for the magnificent Piero della Francesca frescoes in the church of San Francesco. It's also the birthplace of the poet Petrarch (1304–74), the Renaissance artist and art historian Giorgio Vasari, and Guido d'Arezzo (aka Guido Monaco), the inventor of contemporary musical notation. Arezzo dates from pre-Etruscan times, when around 1000 BC the first settlers erected a cluster of huts. Arezzo thrived as an Etruscan capital from the 7th to the 4th century BC, and was one of the most important cities in the Etruscans' anti-Roman 12-city federation, resisting Rome's rule to the last.
The city eventually fell and in turn flourished under the Romans. In 1248 Guglielmino degli Ubertini, a member of the powerful Ghibellines, was elected bishop of Arezzo. This sent the city headlong into the enduring conflict between the Ghibellines (pro-emperor) and the Guelphs (pro-pope). In 1289 Florentine Guelphs defeated Arezzo in a famous battle at Campaldino. Among the Florentine soldiers was Dante Alighieri (1265–1321), who often referred to Arezzo in his Divine Comedy. Guelph–Ghibelline wars continued to plague Arezzo until the end of the 14th century, when Arezzo lost its independence to Florence.