Germany
Frederick III
Sigismund died in December 1437. He nominated his son-in-law Albert, who was crowned 1 January 1438. He immediately had to go east to deal with a Turkish invasion across the Danube River and died while still on campaign in Serbia on 27 October 1439.
Albert was succeeded by his cousin Frederick, a Habsburg ruling Styria, Carinthia and Carniola. From Frederick's reign on, the Habsburgs ruled the Empire, and the heart of their power lay in Austria.
In theory, Frederick was also King of Bohemia and King of Hungary. But Albert's widow gave birth to a son, Ladislas, three weeks after Albert's death. The boy was raised at Frederick's court, more or less as a privileged prisoner.
Austria formed the center of Frederick's attention for the first fifteen years or so. The child Ladislas technically stood to inherit large parts of the duchy, and Frederick had a younger brother who had legitimate claim to other parts. The Austrian estates regarded Frederick as a Styrian foreigner and resented his financial policies. He was twice besieged in Vienna.
Ladislas died in 1457, though his death did little to settle the Hungarian question, for other claimants came to the fore. It was to be some time yet before the Habsburgs ruled Hungary. Frederick's younger brother, Albert IV, died in 1463. The two deaths, plus the Emperor's own patient persistence, at least brought most of Austria into Habsburg hands. Ironically, the Tyrol, the original home of the Habsburgs, was still ruled by another relative, the Archduke Sigismund. He was pensioned off in 1490, completing the Austria of the Habsburg family. Taken together, the lands at least provided sufficient income to keep a ducal court, though far from enough to finance an empire.