In 1617, Emperor Matthias had his fiercely Catholic brother Ferdinand of Styria elected King of Bohemia, but in 1618 Protestant Bohemian noblemen, who feared losing their religious freedom, started the Bohemian Revolt. The Revolt started by the unplanned second Defenestrations of Prague and was defeated in 1620 in the Battle of White Mountain near Prague. As consequence the local Protestant noblemen were either executed or expelled from the country while the Habsburgs placed Catholic (and mostly German speaking) nobility in their place. The war, plague, and subsequent disruption led to a decline in the population from over 3 million to some 800,000 people. By 1622, the entire education system was in the hands of Jesuits and all Protestant schools were closed.