Rinaldo d'Este
Rinaldo d'Este (1230–1251) was the only son of Azzo VII d'Este, Guelph lord of Ferrara. In 1239 his father gave him to the Emperor Frederick II as a hostage in pledge of loyalty. When Azzo joined the papal side, Rinaldo was imprisoned in Apulia, where he died, probably poisoned, in 1251.
His illegitimate son Obizzo was born around 1247 to a Neapolitan laundress. The boy was legitimised by Pope Innocent IV in 1252 and inherited Ferrara in 1264.