 Although Albert's reign spanned only one year, he was succeeded by his Leopoldian cousin, Duke 
Ernest's son, Frederick V, who eventually reunified the Habsburg territories, after the extinctions of the Albertinian line (1457) and the Elder Tyrolean line (1490).Duke Frederick was crowned Holy Roman Emperor (as Frederick III) in 1452; he formally acknowledged the elevation of Austria to an archduchy one year later, whereafter all Habsburg princes bore the archducal title.Only two non-Habsburgs reigned the Empire between 1438 and 1806, when Emperor Francis II resigned.