From a German surname, itself from the Germanic given name LEUTHAR. The surname was borne by Martin Luther, a 16th-century monk and theologian, who started the Protestant Reformation by nailing his famous 95 theses to a church door. It has since been used as a given name in his honour, especially among Protestants. A notable bearer from the modern era was the American civil rights leader Martin Luther King (1929-1968).