"Ferdinand I (Spanish: Fernando I) (10 March 1503 – 25 July 1564) was Holy Roman Emperor from 1556, king of Bohemia and Royal Hungary from 1526, and king of Croatia from 1527 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 Germany and developed encouraging relationships with German princes.
The key events during his reign were the contest 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 could not conquer the major part of Hungary. His flexible approach to Imperial problems, mainly religious, finally brought more result than the more confrontational attitude of his brother." - (en.wikipedia.org 13.03.2020)
