See:

• Frederick II, Holy Roman Emperor (1194-1250, emperor 1211-1250)
• Frederick II of Austria (?-1246, duke of Austria 1230-1246)
• Frederick II, Margrave of Brandenburg (1413-1470, margrave 1440-1470)
• Frederick II of Denmark and Norway (1534-1588, king 1559-1588)
• Frederick II of Prussia (1712-1786, king 1740-1786), better known as Frederick the Great