The Origins of the Limitanei

[Flavivs Aetivs]

Actually it seems that by the 5th century the Romans finally managed to standardize the titles of Dux and Comes, with a few minor exceptions. Take for example the Comes Tractis Aremoriciani command, which was a limitanei command. In 464 it belonged to Paulinus, a commander under Aegidius whose only record is that he fought alongside Childeric and Odovacar against the Visigoths in 464 (and died). Aegidius, under Aetius, probably held the title of Dux Belgicae Secundae, while Ricimer was probably Comes Foederatorum and Majorian was Magister Militum per Gallias. Aegidius, in 464, had had the title of Magister Militum per Gallias stripped from him and given to Agrippinus, so he probably was Dux Belgicae Secundae, based out of Novidunum (Augusta Suessionem). Paulinus was under his command, which shows an evident structure of the Comes Limitis (not Comes rei Militaris, who commanded the field armies) being under the command of Dux Limities.

Comes rei Militaris, on the other hand, was a separate title of basically equivalent rank to the Dux, but neither the Dux nor the Comes had command over each others' forces really.

BTW, I'm led to believe that Praepositus Ripae might be one of the commands missing from the Notitia.