In 1525, grand master Albert of the Teutonic Order converted the lands held by his order into a duchy, becoming the duke of Prussia. His successors built on this, with Frederick I proclaiming himself king in 1701. This continued until 1918, when the last king (by then also German Emperor) abdicated, and the monarchy was abolished. Can you name the 14 people who served as duke or king of Prussia?
Regnal numbers must be used, unless an epithet is used instead. Both German and English names are accepted.