As a German surname, Luther is derived from a Germanic

Germanic languages

The Germanic languages constitute a sub-branch of the Indo-European language family. The common ancestor of all of the languages in this branch is called Proto-Germanic , which was spoken in approximately the mid-1st millennium BC in Iron Age northern Europe...

 personal name compounded from the words liut, "people", and heri, "army". As a rare English surname, it means "lute player" (Hanks and Hodges 1988). Luther is also derived from the ancient Greek eleutherius, a liberator. Luther has also been regularly used as a given name in English speaking countries in modern times, originally in honor of Martin Luther

Martin Luther

Martin Luther was a German priest, professor of theology and iconic figure of the Protestant Reformation. He strongly disputed the claim that freedom from God's punishment for sin could be purchased with money. He confronted indulgence salesman Johann Tetzel with his Ninety-Five Theses in 1517...

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