The Peace of Pressburg, which was signed on 1 May 1254 and ceded Styria to Hungary, ended the war situation in the region, which lasted more than a decade, thus Amadeus could start his episcopate under calm and relatively peaceful conditions. In the territory of his diocese and the northwestern part of Transdanubia, Amadeus took part in that process, when Béla IV set up special commissions which revised all royal charters of land grants made after 1196. During the implementation of Béla's land reform in the first half of the 1250s, Amadeus frequently acted as co-judge in various lawsuits and border determinations in his diocese, alongside secular barons and his deputy, the archdeacon of Rábaköz. During his activity, Amadeus recovered several landholdings and estates for the Crown. He restored law and administration in the region, which had collapsed after the Mongol invasion and the subsequent Austrian and Bohemian raids. For his advice, Béla IV settled the customs and port duties in Győr and the surrounding area (for instance, Abda and Füzitő), and restored the right to hold markets to Széplak, which was owned by the "gens" Osl. Amadeus consecrated the parish church of Ják in 1256, today the most complete Romanesque cathedral in Hungary. The internal peace had broken, when the Styrian noblemen rose up in rebellion against the Hungarian rule in 1258, which caused a war between Béla and Ottokar until 1260.