The article focuses on the figure of a thirteen century Tuscan bishop , who died on the famous battlefield of Campaldino. While not neglecting his pastoral duties, which included an accurate visit of the whole diocese, Ubertini was mainly engaged in political activity, culminating in his lordship over the city of Arezzo. The particular turbulence of this period allowed him to play a significant role not only at the local level, but in regional politics as well. He thus represented a type of bishop which was becoming uncommon but had not as yet disappeared.
Keywords: Arezzo, Late Middle Age, Bishops, Communes, Lordship