 Henry's son, Frederick II, Holy Roman Emperor – the first emperor since the 10th century to actually base himself in Italy – attempted to return to his father's task of restoring imperial authority in the northern Italian Kingdom, which led to fierce opposition not only from a reformed Lombard League, but also from the Popes, who had become increasingly jealous of their temporal realm in central Italy (theoretically a part of the Empire), and concerned about the hegemonic ambitions of the Hohenstaufen emperors.Frederick II's efforts to bring all of Italy under his control failed as signally as those of his grandfather, and his death in 1250 marked the effective end of the Kingdom of Italy as a genuine political unit.Conflict continued between Ghibellines (Imperial supporters) and Guelfs (Papal supporters) in the Italian cities, but these conflicts bore less and less relation to the origins of the parties in question.