Note 838 — CANTO XXXIII.
James Romanes Sibbald translation
My sons: According to Dante, taken literally, four of Ugo were imprisoned with him. It would have hampered him to explain that two were grandsons—Anselmuccio and Nino, called the Brigata at line 89, grandsons by their mother of King Enzo, natural son of Frederick II.—the sons being Gaddo and Uguccione, the latter Ugo’s youngest son.