Sigismund of Luxembourg married Queen Mary of Hungary in 1385 and was crowned King of Hungary soon after. He fought to restore and maintain authority to the throne. Mary died in 1395, leaving Sigismund the sole ruler of Hungary. In 1396, Sigismund led the Crusade of Nicopolis, but was decisively defeated by the Ottoman Empire. Afterwards, he founded the Order of the Dragon to fight the Turks and secured the thrones of Croatia, Germany and Bohemia. Sigismund was one of the driving forces behind the Council of Constance (1414–1418) that ended the Papal Schism, but which also led to the Hussite Wars that dominated the later period of his life. In 1433, Sigismund was crowned Holy Roman Emperor and ruled until his death in 1437.

Historian Thomas Brady Jr. remarks that Sigismund "possessed a breadth of vision and a sense of grandeur unseen in a German monarch since the thirteenth century". He realized the need to carry out reforms of the Empire and the Church at the same time. But external difficulties, self-inflicted mistakes and the extinction of the Luxembourg male line made this vision unfulfilled.