Grosseto was one of the main Etruscan cities. The city was under the control of the Aldobrandeschi family. In 1137, the city was captured by German soldiers under the control of Duke Henry X of Bavaria. In 1151, the people of Grosseto agreed to be under the control of Siena. In 1222, the city returned to the Aldobrandeschi. When Siena captured the lands of the Aldobrandeschi in 1244, Grosseto was under their control again. The city tried to free itself in 1266 and 1355 but failed.