凯撒（Caesar）在德文（Kaiser）之中意为「君主」，德意志族裔的君主都会用这个称呼。俄裔君主沙皇使用Tsar都是自凯撒而来。女性君主使用「Kaiserin」一词。

Kaiser is the German word for "emperor". Like the Bulgarian, Serbian and Russian Czar it is directly derived from the Roman emperors' title of Caesar, which in turn is derived from the personal name of a branch of the gens (clan) Julia, to which Gaius Julius Caesar, the forebear of the first imperial family, belonged. Although the British monarchs styled "Emperor of India" were also called "Kaisar-i-Hind" in Hindi and Urdu, this word, although ultimately sharing the same Latin origin, is derived from the Greek:Καῖσαρ (kaisar), not the German Kaiser.