In the course of dynastic succession, power often devolved upon children. As their young age meant that they were not capable of ruling, a guardian was appointed to assist them until they reached majority.
When King Albrecht II died suddenly only a year or so after assuming the reins of power he did not yet have a male heir: it was not until months after his death that his son Ladislaus was born in 1440 and for this reason given the byname ‘Postumus’. The quick thinking of a lady-in-waiting, Helene Kotanner, ensured that the infant became King of Hungary: she managed to steal the Crown of St Stephen and take it to the baby’s mother, Elizabeth.
A few weeks after his birth, Ladislaus, who was also heir to the Lower Austrian lands, was crowned King of Hungary. His uncle, later Emperor Frederick III, was appointed his guardian: as the eldest of the Habsburgs, he was charged with enforcing Ladislaus’s claims to the Bohemian and Hungarian crowns and securing the unity of the House of Austria. Habsburg possession of the Hungarian crown was however only temporary: the Hungarian Estates refused to recognize Frederick as guardian and elected another imperial governor.
In 1442 Frederick III was crowned king of the Holy Roman Empire in Aix-la-Chapelle. However, the power of the Roman-German king at this time had reached a nadir: for almost 30 years Frederick III did not set foot in the core territories of the Empire. Frederick was not especially popular in Austria and faced strong opposition from the nobility: the League of Mailberg demanded an end to his guardianship over Ladislaus. Frederick reacted in typical fashion, evading conflict by travelling to Rome for his coronation and simply taking his ward with him.
Following Frederick’s return, his opponents resorted to violence: an army of the Estates besieged the emperor in Wiener Neustadt in 1452, forcing him to release the twelve-year-old Ladislaus from his guardianship for once and all. Ladislaus concentrated his ambitions on Hungary and Bohemia, and in due course was crowned King of Bohemia in 1453. However, he died shortly afterwards, aged just seventeen. There were rumours that he had been poisoned, but the most likely cause of his death was bubonic plague. His death occasioned yet another re-arrangement of the Habsburg inheritance: both Emperor Frederick III and his brother Duke Albrecht VI staked their claims, leading to renewed fraternal strife in the House of Habsburg.