The Emperor of Germany (German: Kaiser) is the constitutional head of state of Germany. The position has existed since 1871 when the country was first unified. By virtue of the office, the Emperor of Germany is also the King of Prussia. It is from the first King of Prussia that the 'number' of an emperor is counted - thus, Frederick III was the first Emperor by that name. The ruling dynasty in Germany is the House of Hohenzollern, which has ruled Germany since the Empire was founded.