Frederick I, also called Frederick Barbarossa, was crowned Emperor in 1155. He emphasized the "Romanness" of the Empire, partly in an attempt to justify the power of the Emperor independent of the (now strengthened) Pope. An imperial assembly at the fields of Roncaglia in 1158 reclaimed imperial rights in reference to Justinian's Corpus Juris Civilis. Imperial rights had been referred to as regalia since the Investiture Controversy, but were enumerated for the first time at Roncaglia as well. This comprehensive list included public roads, tariffs, coining, collecting punitive fees, and the investiture, the seating and unseating of office holders. These rights were now explicitly rooted in Roman Law, a far-reaching constitutional act. Frederick's policies were primarily directed at Italy, where he clashed with the increasingly wealthy and free-minded cities of the north, especially Milan. He also embroiled himself in another conflict with the Papacy by supporting a candidate elected by a minority against Pope Alexander III (1159–81). Frederick supported a succession of antipopes before finally making peace with Alexander in 1177. In Germany, the Emperor had repeatedly protected Henry the Lion against complaints by rival princes or cities (especially in the cases of Munich and Lubeck). Henry gave only lackluster support to Frederick's policies, and in a critical situation during the Italian wars, Henry refused the Emperor's plea for military support. After returning to Germany, an embittered Frederick opened proceedings against the Duke, resulting in a public ban and the confiscation of all his territories. During the Hohenstaufen period, German princes facilitated a successful, peaceful eastward settlement of lands previously uninhabited or inhabited sparsely by West Slavs. German speaking farmers, traders, and craftsmen from the western part of the Empire, both Christians and Jews, moved into these areas. The gradual Germanization of these lands was a complex phenomenon that should not be interpreted in the biased terms of 19th century nationalism. The eastward settlement expanded the influence of the Empire to eventually include Pomerania and Silesia – also due to intermarriage of the local, still mostly Slavic, rulers with German spouses. Also, the Teutonic Knights were invited to Prussia by Duke Konrad of Masovia to Christianize the Prussians in 1226. The monastic state of the Teutonic Order (German: Deutschordensstaat) and its later German successor state of Prussia were, however, never part of the Holy Roman Empire. In 1190, Frederick Barbarossa participated in the Third Crusade and died in Asia Minor. Under his son and successor, Henry VI, the Hohenstaufen dynasty reached its apex. Henry added the Norman kingdom of Sicily to his domains, held English king Richard the Lionheart captive and aimed to establish a hereditary monarchy, when he died in 1197. As his son, Frederick II, though already elected king, was still a small child and living in Sicily, German princes chose to elect an adult king, which resulted in the dual election of Frederick Barbarossa's youngest son Philip of Swabia and Henry the Lion's son Otto of Brunswick, who competed for the crown. Otto prevailed for a while after Philip was murdered in a private squabble in 1208 until he began to also claim Sicily. Pope Innocent III, who feared the threat posed by a union of the Empire and Sicily, now supported Sicily's king Frederick II, who marched to Germany and defeated Otto. After his victory, Frederick did not act upon his promise to keep the two realms separate – though he had made his son Henry king of Sicily before marching on Germany, he still reserved real political power for himself. This continued after Frederick was crowned Emperor in 1220. Fearing Frederick's concentration of power, the Pope finally excommunicated the Emperor. Another point was the crusade, which Frederick had promised but repeatedly postponed. Now, though excommunicated, Frederick led the crusade in 1228, which however ended in negotiations and a temporary restoration of the Kingdom of Jerusalem. Despite his imperial claims, Frederick's rule was a major turning point towards the disintegration of a central rule in the Empire. While concentrated on establishing a modern, centralized state in Sicily, he was mostly absent from Germany and issued far-reaching privileges to Germany's secular and ecclesiastical princes: In the 1220 Confoederatio cum principibus ecclesiasticis, Frederick gave up a number of regalia in favour of the bishops, among them tariffs, coining, and fortification. The 1232 Statutum in favorem principum mostly extended these privileges to secular territories. Although many of these privileges had existed earlier, they were now granted globally, and once and for all, to allow the German princes to maintain order north of the Alps while Frederick wanted to concentrate on Italy. The 1232 document marked the first time that the German dukes were called domini terr?, owners of their lands, a remarkable change in terminology as well.