The "Bulgaria of the West" without the whole Kleidon part.The Bulgaria of the West you say? Hmmm....The Byzantines had Basil II the Bulgar Slayer so the Romans would have a Francicus Maximus or Gallicus Maximus
No they won’t. I might even ditch them soon. Having one single successful dynasty for the entire length of this timeline is not my aim. Rather the Nepotians will represent an age of necessary recovery before starting again a new era of Crisis like the Third century. And if something like the Third century happens again, it’ hard to imagine any dynasty surviving through this many disasters and and losses.What they need is a long and stable dynasty that establishes the tradition of peaceful succession from father to son. This was how the Capetians strengthened their hold on France and gradually expanded the power of a King away from the weakened elective monarchy. The Romans had many opportunities in the form of the Macedonian dynasty, Isaurian dynasty, Constantinian dynasty, Julio-Claudian dynasty, Nerva-Antonine, Severan, etc. Perhaps the dynasty of Nepos accomplishes this purpose.
But I never implied that these invasions will happen out of the blue. Specific circumstances will allow the Arabs to expand against the empire, though it won’t be just an "external invasion". Some of these circumstances will have to be same of OTL for obvious reasons (the need to weaken both empire is still there) but others are going to be different. Right now everything seems perfect for the empire (more or less) but who can say it will be so around the end of the century.Still doesn't really make much sense to me as to how they beat the Romans. Both the Romans and Persians have their own buffer/client-states of the Lakhmids and Ghassanids. If something were to threaten them, then this would draw the notice of the Persians or Romans. The Eastern Empire is also more stable here with control over its provinces and no Gothic War or massive war with the Persians to sap their resources. The Romans fought four times with the Persians. The fought under Justin and Justinian in the Lazic War over Iberia, Khosrau's invasion of the East, when Justin II refused to pay tribute, and when Khosrau II invaded after Maurice was assassinated. There also was no civil war like the one Heraclius started with Phocas.