POD: Philip the Handsome dies in 1495.
Holy Roman Emperors
1452-1493: Fredrick III (Hapsburg)
1493-1519: Maximilian I (Hapsburg) [1]
[1] To say Philip the Handsome's death was devastating would be an understatement. The Hapsburg legacy was resting on his shoulders. Although there was a chance his father could have a son with his third wife, it was still a tragedy. His death also meant the alliance with the Catholics monarchs was now defunct. Maximilian pushed for the new Duchess of Burgundy, Margaret of Austria to be married to the Crown Prince of Spain, but her council of advisors wanted a more domestic mach. She was married instead to Charles II, Duke of Guelders in 1497, ruling together over Burgundy. King Fernando and Queen Isabel would marry their son, Juan to Anne of Navarre, their daughter Juana would marry King Manuel of Portugal. With Burgundy wanting to remain independent, although Margaret would never forget being jilted by the late King Charles of France, they would make a tentive peace with France, staying out of the Italian wars in the first years of the 15th century.
With Philip's death, Maximilian's oldest male relative, before the births of his grandsons, was his nephew, Wilhielm of Bavaria, son of his sister Kunigunde of Austria and her husband, Albert IV, Duke of Bavaria. Kunigunde immediately began pushing her son forward, believing that he was the obvious choice, despite only being three-years-old. Meanwhile the Duchess of Burgundy and Guelders soon blessed her husband with a son in 1498, who she named Charles. The two women would often makes excuses to visit Maximilian in Vienna, often bringing their sons along with them.
Maximilian tried to have a son with his third wife, Bianca Maria Sforza, despite finding her uneducated and childish. Unfortunately, their union would only produced a daughter, albeit healthy, named Mary for Maximilian's first wife. When Bianca died in 1510, Maximilian tried for a fourth wife, but by then his health had become worse and he decided instead to invest his time grooming the heir he had, giving his chosen successor the kingdom of the Romans. He then gave hefty bribes to the Prince-Electors to ensure his chosen heir's victory. He is famously recorded saying "____ may not be of my dynasty, but blood of blood and will carry out the Hapsburg legacy all the same." In 1519, he died, ending the Hapsburg rule.