On this day in 1619 Ferdinand II was elected emperor of the Holy Roman Empire.
With the Oñate treaty, Ferdinand obtained the support of the Spanish Habsburgs in the succession of his childless cousin Matthias, in exchange for concessions in Alsace and Italy.
His devout Catholicism caused immediate turmoil in his non-Catholic subjects, especially in Bohemia. He did not wish to uphold the religious liberties granted by the Letter of Majesty conceded, signed by the previous emperor, Rudolph II, which had guaranteed the freedom of religion to the nobles and the inhabitants of the cities.
Additionally, Ferdinand was an absolutist monarch and infringed several historical privileges of the nobles.
Given the relatively great number of Protestants in the kingdom, including some of the nobles, the king’s unpopularity soon caused the Bohemian Revolt.
The Second Defenestration of Prague of 22 May 1618 is considered the first step of the Thirty Years’ War.