He was born in Pistoia, Tuscany. His full name was Guittoncino dei Sinibaldi or, Latinised, Cinus de Sighibuldis. His father was a noble man from the House of Sinibaldi. He received his doctorate from the University of Bologna, where he studied under Dinus de Rossonis, and taught law at the universities of Siena, Florence, Perugia, and Naples. In 1334, he was elected Gonfaloniere of Pistoia, but did not take up the office.
