At one time the Heruli were considered to be a Germanic tribe but scholars are now of the opinion in the main that instead of being a tribe they were in fact members of a cultic association. Historical records indicate that Heruli were involved in wars during the 3rd to 6th centuries CE in Italy, Greece, Spain, Gaul, Scotland and in North Africa. These were highly trained Germanic warriors that were members of Männerbünde and were extremely mobile horse-riding shock troops that would have been deployed in difficult situations.
However as I have indicated by the use of the term cultic they were not merely warriors but also highly trained Rune Masters.
"Hoefler's very convicing theory connected the campaigns of the Heruli with the expansion of the runes. Helmet A from Negau would serve as a link, as it bears the name Erul, a Germanic centurion in Roman service from the 1st or 2nd century A.D. If this is the case, then members of the Heruli (like the above named Erul) would have created the runic alphabet on Etruscan and Roman models at this early stage. This knowledge of runes could have spread quickly as far as Scandinavia because of the rigid organisation and great mobility of the bands of Heruli. As a result, it is likely that for a long time the knowledge of the runes would have been considered as the privilege of the members of this band of warriors who were bound to Odin by cult." (Dictionary of Northern Mythology, Rudolf Simek)
Dr Stephen Edred Flowers (Edred Thorsson) discusses in his Runes and Magic how the terms erilaR and gothi "later evolved into clearly defined social functions, or official titles (cf. ON jarl < erilaR, and gothi < gud-on". He also reminds us of the connection between the OE eorl ('warrior') and erilaR. He states "One has only to compare OE eorl: 'warrior', to see that erilaR must have had quite a broad semantic field. On the other hand it cannot be doubted that erilaR, whether it was originally an ethnic or functional designation, must have taken on the special, virtually titular, meaning of 'rune-master' in the North Germanic territory from between ca. 450 and 600, however the actual etymology of erilaR < *er-il-az remains obscure".
Likewise Simek theorises that the time of the spread of the runes into North Germanic territory (ie Scandinavia) occurred at about this time:
"During the conquest of Italy by the Odoaker in 476 A.D., the Heruli belonged to his main troops. After the downfall of the Danubian state of the Heruli by the Langobards, the majority of the Heruli migrated to Scandinavia."
As Simek points out the Heruli were a cultic organisation of warriors who were "bound to Odin". Odin is thus the lord of the Heruli, being master of both war and of the runes. It is clear to me that no-one can call him or herself a Rune Master unless they are bound to Him. Simek is wrong to assume as so many scholars do that the runes have their origin in the alphabet of another people. This article is not the place to discuss this but the runes had developed as special sacred and magical signs from the Proto-Germanic period onwards and they are just a remnant of our lost runic heritage. It is also worth remembering that the cult of Odin imported itself into Scandinavia from Germania, no doubt in part at least due to groups like the Heruli.
The association of the term erilaR with the ON jarl or the OE eorl (earl) is an ancient one that can be found in the myth of the founding of the Germanic caste system in the Lay of Rig or the Rigsthula in the Elder Edda. The Jarl caste is the 3rd one to be sired by Rig and Rig calls the child Jarl-Rigr. Jarl sires children and names them Adal, Barn, Sonr and Konr ungr, in other words, noble, child, son and young descendant or king. Both Simek and Flowers reject the notion that Rig is Heimdall, in favour of Rig being Odin, the sire of nobles and kings and the lord of the runes. Rig teaches Jarl the runes and I do not consider it to be merely a coincidence that the Rune Masters of Germania should be designated as Heruli which we know via erilaR is cognate with jarl/eorl. There is a mystery here for us to ponder on.