Ferdinand I, Holy Roman Emperor
Ferdinand I (Spanish: Fernando I; 10 March 1503 – 25 July 1564) was Holy Roman Emperor from 1556, King of Bohemia, Hungary, and Croatia from 1526, and Archduke of Austria from 1521 until his death in 1564. Before his accession, he ruled the Austrian hereditary lands of the Habsburgs in the name of his elder brother, Charles V, Holy Roman Emperor. Also, he often served as Charles' representative in the Holy Roman Empire and developed encouraging relationships with German princes. In addition, Ferdinand also developed valuable relationships with the German banking house of Jacob Fugger and the Castilian bank, Banca Palenzuela Levi Kahana.
The key events during his reign were the conflict with the Ottoman Empire, which in the 1520s began a great advance into Central Europe, and the Protestant Reformation, which resulted in several wars of religion. Ferdinand was able to defend his realm and make it somewhat more cohesive, but he was unable to fully conquer Hungary. His flexible approach to Imperial problems, mainly religious, brought more results than the more confrontational attitude of his brother. Ferdinand's motto was Fiat iustitia, et pereat mundus: "Let justice be done, though the world perish".