I suppose a better pod would be a revival of the Soisson kingdom in the early 6th century, when the Frankish realm was split into multiple parts.
Thing is, the so-called Soissons kingdom might not have an historical reality to begin with.
Gregory of Tours does mention (really, really briefly*) Syagrius as a king in Soissons, and there's little doubt he might have enjoyed a special influence (would it be only trough his prestigious family ties) in northern Gaul outside the region he immediatly controlled (no other leader is mentionned, except Arbogast of Treves that was probably independent of Syagrius) but he was an "unofficial" ruler since years, unacknowledged by the imperial courts, while Clovis was still acknowledged as the "official" ruler of Belgica Secunda (it's even possible that Syagrius took back Soissons, a military arsenal location, from Childeric at some point).
In some geopolitical aspects, the Gallo-Roman situation was close to what existed in post-Imperial Britain, with divided loyalties and local forces having to supply their own defenses. But while in Britain, thecommand went to military leaders with if ambiguous clear de facto legitimacies (Ambrosius Aurelianus is a good exemple), in Gaul it remained with clearly identified and, at least from a far, sanctioned individuals : when Syagrius became a rogue ruler after the fall of WRE, Clovis became the onle "official" Roman military ruler in northern Gaul and, from this, the only more or less legal ruler in the region, as were other Romano-Barbarian kings.
Of course, Syagrius certainly didn't see things this way, but several Gallo-Romans may have, like several Gallo-Romans or Hispano-Romans nobles joined Gothic or Burgondian courts (there is nothing indicating that the integration of Gallo-Roman nobility was anything but smoothles under Merovingians).
Eventually, Syagrius ruled a small territory in Northern Gaul (probably along a Noyon-Soissons-Senlis triangle), contrary to the unsourced idea of a Gallo-Roman state spawning from Channel to Meuse (which was essentially a way to "fill the gap" on a map by XIXth cartographers).
Syagrius was hardly unique, while arguably the best known of these regional Roman rulers that may have fought but eventually joined with Barbarians. A non exhaustive list would include Vicentius in Taracconensis; Apollinaris Sidonius and Ecdicius in Auvergne; Victorius, Desiderius and Namatius in Aquitaine; Syagrius (same family, different guy) and Avitus in Provence, Arbogast in Germania, etc.
In fact, it could be considered that before the Battle of Déols, Northern Gaul was ruled by an imperially sanctionned Britto-Gallo-Franco-Roman continuum, on which the Franks played a decisive part since the IVth century (many Franks, possibly related to Merovingians, were master militiae in Gaul and for the WRE). Childeric and Clovis seems to have beneficied both from their prestige as Merovingians over the smaller Frankish kingdoms (let's remember from the Vth and VIth century that division among Franks never really was that of a geopolitical hinderance among Franks) and relations with Gallo-Roman ensemble.
And of course, even at this points, Franks (as virtually all Barbarians within Romania) were importantly romanized and made of provincial Roman populations : material culture-wise, it's really difficult to see the difference between a Franko-Roman and a Gallo-Roman, and most of the distinctive features attributed to Franks in the Vth were either made up on the spot (fransicae were "borrowed" from eastern Barbarians, and virtually unknown beforehand, special clothing features) or part of late Roman culture ("Merovingian" burials, Frankish laws, etc.).
Frankish language disappeared as an actually used one since the late Vth at best, even if it survived in ceremonial and legal uses, while Franks still in Germany probably switched to related German dialects.
It's quite important to understand that Franks, as Barbarians in general, mostly inherited a late Roman civilisation that was significantly Barbarised, but that much more significantly romanized Barbarians right from the beggining.
Not that Frankish hegemony was a given : we discussed a bit about it with
@SeaCambrian f
ew days ago.
Didn't the Oaths of Strasbourg refer to the inhabitants of West Francia as speaking 'Roman'?
In the early IXth century, romance languages were called "Rustic Roman language" but that was appliable for mostly every romance speech in Carolingia, as you didn't yet have a differenciation between Northern and Southern Gallo-Romance speeches (and I agree with Cantalusa when he argues the romance part of the Oath is a composite of proto-Oil and proto-Oc languages).
The romance part of the oath specify the language is "romana lingua" Roman/Romance language, but this is not referring to inhabitants or peoples. Even late in the middle ages, French and Occitan were called as such without any identitarian value.
The identitarian ethnonymy and endonymy between northern and southern population was rather Franks/Aquitains-Goths up to the XIth century (altough before the VIIIth century, southern populations tended to call themselves Romans)