The Nuttall Encyclopedia
Tyrant of Pisa; was of the Guelph party; celebrated for his tragic fate; having fallen into the hands of his enemies, he was in 1288 thrown into a dungeon along with his two sons and two grandsons, and starved to death, a fate which suggested to Dante one of the most terrible episodes in his "Inferno"; the dungeon referred to has since borne the name of the "Tower of Hunger."
Wood, James, ed. Entry for 'Ugolino, Count'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/u/ugolino-count.html. Frederick Warne & Co Ltd. London. 1900.