Thomas II was the Lord of Piedmont from 1233 to his death, Count of Flanders jure uxoris from 1237 to 1244, and regent of the County of Savoy from 1253 to his death, while his nephew Boniface was fighting abroad. He was the son of Thomas I of Savoy and Margaret of Geneva.

The lordship of Piedmont, later the principality of Piedmont, was originally an appanage of the County of Savoy, and as such its lords were members of the Achaea branch of the House of Savoy. The title was inherited by the elder branch of the dynasty in 1418, at about which time Savoy was elevated to ducal status and Piedmont to princely status. When the House of Savoy was given the Kingdom of Sardinia, the Savoyards used the style of Prince of Piedmont for their heir apparent. This first came into use by Prince Victor Amadeus of Savoy.