The rulers of the rump state, notably its final ruler Syagrius, were referred to as "kings of the Romans" (Latin: rex Romanorum) by the Germanic peoples surrounding Soissons, with the polity itself being identified as the Regnum Romanorum, "Kingdom of the Romans", by the Gallo-Roman historian Gregory of Tours.

When Majorian was killed on the orders of Ricimer in 461, Aegidius maintained his own power in the remnants of Roman Gaul against Franks to his east and Visigoths to his south.

During Majorian's reign, that corridor was annexed by the Germanic tribes now occupying Gaul, thus effectively cutting off Aegidius and his citizens from the Empire.

These provinces were annexed by the Visigoths and Burgundians in the years 462–477, which left the remaining Roman territories in Gaul isolated.

Aegidius was allied with the Alans, and with Childeric I, king of the Salian Franks of Tournai, and helped them defeat the Visigoths at Orléans in 463.

It is possible that the Groans of the Britons, referring to a Romano-British request for military assistance after the Roman departure from Britain, may have been addressed to Aegidius.

Syagrius governed using the title of dux (a provincial military commander), but the neighboring Germanic tribes referred to him as "King of the Romans"; hence one of the nicknames of his enclave.

The portions centred around Soissons and Paris eventually developed into the kingdom of Neustria, which remained one of the key divisions of the Frankish realm.