On March 15, 1939, shortly after Nazi Germany forced Czech President Emil Hacha (who suffered a heart attack during the negotiations) to hand his nation over to the Germans, Adolf Hitler spent a night in the Prague Castle, "proudly surveying his new possession." During the Nazi occupation of Czechoslovakia in World War II, Prague Castle became the headquarters of Reinhard Heydrich, the Reich Protector of Bohemia and Moravia. According to a popular rumor, he is said to have placed the Bohemian crown on his head; old legends say a usurper who places the crown on his head is doomed to die within a year. Less than a year after assuming power, on May 27, 1942, Heydrich was ambushed during Operation Anthropoid, by British-trained Slovak and Czech resistance soldiers while on his way to the Castle, and died of his wounds - which became infected - a week later. Klaus, his firstborn son, died the next year in a traffic accident, also in line with the legend.