The name is attested with some frequency in Medieval Germany throughout the 8th to 11th centuries, in the spelling variants Arnulf, Arnulph, Arnolf, occasionally also as Arenulph, Harnulf, Harnolf, Harnolph.
In the 9th century, Arnulf of Carinthia was the ruler of East Francia and was crowned Holy Roman Emperor in 896.
There was an Anglo-Saxon cognate, Earnulf (Ernulf), which was assimilated to the Frankish form of the name after the Norman conquest.
The name is also attested in medieval Scandinavia, as Old Norse Arnúlfr (Ærnulfr, Ǫrnólfr, Ǫrnulfr, Old Swedish Ærinolf, Ærnolf, Ärnulf).
[1] Scandinavian dialectal and regional variants of the name include Annul, Annulv, Anul, Arnolv, Arnulv, Örnólfur, Ørnolvur, Örnulf, Ørnulf, Ørnulv.