Question: The great-great-grandfather of current head of the House of Hohenzollern held what official title?
Sentence (from "Wilhelm II, German Emperor"): Wilhelm II or William II (German: "Friedrich Wilhelm Viktor Albert von Preußen", English: Frederick William Victor Albert of Prussia; 27 January 18594 June 1941) was the last German Emperor ("Kaiser") and King of Prussia, ruling the German Empire and the Kingdom of Prussia from 15 June 1888 to 9 November 1918.
Relevant evidence: Yes