of Carinthia. Not until 1004 could the new German King Henry II of Germany, by the aid of Bishop Leo of Vercelli, move into Italy to have himself crowned rex Italiae. Arduin ranks as the last domestic "King of Italy" before the accession of Victor Emmanuel II in 1861. Henry's Salian successor Conrad II tried to confirm his dominion against Archbishop Aribert of Milan and other Italian aristocrats (seniores). While besieging Milan in 1037, he issued the Constitutio de feudis in order to secure the support of the vasvassores petty gentry, whose fiefs he declared hereditary. Indeed, Conrad could stable his rule, however, the Imperial supremacy in Italy remained contested. Staufer The cities first demonstrated their increasing power during the reign of the Hohenstaufen Emperor Frederick Barbarossa (1152–1190), whose attempts to restore imperial authority in the peninsula led to a series of wars with the Lombard League, a league of northern Italian cities, most of the times headed by Milan, and ultimately to a decisive victory for the League at the Battle of Legnano in 1176, that had as its leader the Milanese Guido da Landriano, which forced Frederick to make administrative, political, and judicial concessions to the municipalities, officially ending his attempt to dominate Northern Italy. From then, Italy became a patchwork of autonomous duchies and city-states only nominally tied to the Holy Roman Empire. Frederick's son Henry VI actually managed to extend Hohenstaufen authority in Italy by his conquest of the Norman Kingdom of Sicily, which comprised Sicily and all of Southern Italy. 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