Task: Question Generation
Input (English): Passage: When Matthias Corvinus died from a stroke on 6 April 1490, Frederick was able to regain the Austrian lands. However, he could not enforce the Habsburg succession to the Hungarian throne and in 1491 his son King Maximilian I signed the Peace of Pressburg with Vladislaus Jagiellon, who was elected Matthias' successor in Hungary. The treaty arranged for the return of Matthias' conquests, and the agreement that Maximilian would succeed Vladislaus should he produce no heir. This did not happen as Vladislaus' son Louis II was born in 1506, but the Habsburgs did exert significant pressure on the Jagiellonians with the 1515 First Congress of Vienna in which they arranged two royal weddings of Vladislaus' daughter Anne with Maximilian's grandson Ferdinand and of Maximilian's granddaughter Mary with Louis II. The double wedding celebrated at St. Stephen's Cathedral decisively advanced the Habsburg succession agenda. During his reign in Hungary, the new Polish king would go on to undo many of Matthias' efforts, unmaking the reformed system of taxation, the standing army, and the centralized authority of the monarch. Hungary's nobles would act in complicity with this, contributing to the weakening of the country until 1526, when Hungary was defeated by the Ottoman Empire in the Battle of Mohács, whereby King Louis II was killed. The Habsburg archduke Ferdinand of Austria by his marriage with Anne of Bohemia and Hungary claimed the succession, he was enfoffed with the Bohemian kingdom by his elder brother Emperor Charles V and also reached the consent of the Hungarian magnates. He was crowned king in Pressburg  on 24 February 1527, laying the grounds for the transnational Habsburg Monarchy.
Output (English): What was Ferdinand of Austria's relation to Emperor Charles V?