Its historic origin is a title high military or naval dignitaries of early modern Europe sometimes held, for example the (nominal) commander-in-chief of the Dutch Republic's navy (usually the Prince of Orange).

[1] In the German Kriegsmarine of the Second World War, Generaladmiral was a rank senior to an Admiral, but junior to a Großadmiral.

A similar practice was used in the German Army, allowing colonel generals to wear four pips on the shoulder board when engaged in duties befitting a field marshal.

This was purely an honorific rank and for much of its existence, it was awarded only to a person on active duty, usually for the head of the naval department, and typically a descendant of the Romanov royal family.

Gustav III revived the rank in 1780, and the same year issued instructions for the General Admiral, which alone was the King in Council's responsible for naval existence and betterment.

[6] "Admiral General" Aladeen from The Dictator (2012) is a parody of leaders who appoint themselves grandiose military ranks.