As per tradition the kingdoms of Austria and Bohemia are held in personal union. Bohemia's crown dates (officially) from 1212. Austria's a more recent 1898.
The Kings of Bohemia are usually dated from 1212 when the title was confirmed by the Sicilian Bull, though an illustrious line of Dukes stretches back to the early 9th century. Previous dukes did claim the title of king however it was not a hereditary title.
|Henry I||(1306, 1307-1310)|
John of Luxembourg marries Elizabeth, the last heir of Wenceslaus II.
Emperor Charles IV
Emperor Sigismund I
Emperor Sigismund II
Emperor John I
|Henry II of Prague|
Queen Joanna as regent
The death of Henry of Prague before he can reach his majority gives the Bohemian magnates, an opportunity to break with Luxembourg rule. Maximilian of Austria is elected. From that date the King of Bohemia is also Archduke of Austria.