Möller grew up in North Frisia after its conquest by Germany in the German–Danish War of 1864 and attended German universities (Pulsiano and Treharne 2001:447). He began teaching Germanic philology at the University of Copenhagen in 1883 and continued to do so for over thirty-five years (ib.). Also in 1883, he published "Das altenglische Volksepos in der ursprünglichen strophischen Form", 'The Old English Folk Epic in the Original Strophic Form', in which he argued, among other things, that "Beowulf" had been composed in a fixed meter which was corrupted by later poets (ib.).