The Heruls were a tribe from southern Scandinavia, known to be capable seamen and raided in Spain and France. A group migrated to present-day Ukraine in the 3rd century and from there raided around the Black Sea and Eastern Med. The ones that remained in Scandinavia were conquered by the Danes in the 6th century and disappeared from history. (John Haywood, Northmen, p. 28. Head of Zeus, London, 2016)

Until, that is, they were resurrected by head of the Icelandic National Library Barði Guðmundsson in his 1959 book Uppruni Íslendinga (the Origin of the Icelanders). Here, he claims that the Heruls, after having moved to Norway where they stayed for four centuries, ultimately colonised Iceland. His evidence was largely that the Icelanders wrote the Sagas instead of the Norwegians, and hence must have been of different stock.

The theory has been noted from time to time, most amusingly in 1999 when an Icelandic supreme court lawyer wrote an article where he tried to show that since the Icelanders were not descendants of the Norwegians, the Norwegians could make no claim to having discovered America at the 1000 year anniversary of that event (links can be found here: Herúlar. (svavarsson.is).

While it has never been firmly established why the Icelanders proved to be more adept writers than the Norwegians, the disappearance of the Heruls is not much of a mystery. As UCLA professor Patrick J. Geary has shown in The Myth of Nations, tribes disappearing into one another during the migration era, being conquered or willingly merging, was rather the norm.

New DNA research which has shown that Icelanders were rather regular Norwegians (if with a large infusion of Celtic blood) should finally put the Herul theory to bed. And yet they seem to have resurfaced again, now in Lithuania, where some claim them as distant ancestors. Where are the Herul? Here are the Herul!    herulii | Huns | Ancient Germanic Peoples (scribd.com)