Losing popularity among the Hungarian nobility, Sigismund soon became victim of an attempt against his rule, and Ladislaus of Anjou-Durazzo (the son of the murdered King of Naples Charles II of Hungary) was called in and crowned. Since the ceremony was not performed with the Hungarian Holy Crown, and in the city of Székesfehérvár, it was considered illegitimate. Ladislaus stayed only few days in Hungarian territory and soon left it, no longer an inconvenience for Sigismund. In 1408 he founded the Order of the Dragon, which included the most of the relevant monarchs and noblemen of that region of Europe at that time. This was just a first step for what was coming. In 1410 he was elected King of the Romans, making him the supreme monarch over the German territories. He had to deal with the Hussite movement, a religious reformist group that was born in Bohemia, and he presided at the Council of Constance, where the theologist founder Jan Hus, was judged. In 1419 Sigismund inherited the Crown of Bohemia after the death of his brother Wenceslaus of Luxembourg, obtaining the formal control of three medieval states, but he struggled for control of Bohemia until the peace agreement with the Hussites and his coronation in 1436. In 1433 was crowned as Holy Roman Emperor by the Pope and ruled until his death in 1437, leaving as his only heir his daughter Elizabeth of Luxembourg and her husband. The marriage of Elizabeth was arranged with the Duke Albert V of Austria, who was later crowned as King Albert of Hungary in 1437.