Ferdinand I (keizer van het Duitse Rijk ; 1503-1564)
vanaf 1556: keizer Heilige Roomse Rijk der Duitse Natie
vader van keizer Maximiliaan II (1527-1576)
jongere broer van keizer Karel V (1500-1558) van het Habsburgse Rijk (2e zoon van Filips de Schone en Johanna 'de Waanzinnige')
He ruled the Austrian Habsburg possessions as Archduke of Austria most of his public life, at the behest of his elder brother, Charles V, Holy Roman Emperor and King of Spain. Ferdinand was Archduke of Austria from 1521-1564. After the death of his brother-in-law Louis II, Ferdinand ruled as King of Bohemia and Hungary (15261564). When Charles voluntarily retired in 1556, Ferdinand became his successor as Holy Roman Emperor (de facto in 1556, de jure in 1558), while Spain, the Spanish Empire, Naples, Sicily, Milan, the Nethelands, and Franche-Comté went to Philip, son of Charles.