How will a victory here change the empire? If Theodosius doesn’t come to the throne then the empire won’t have to deal with the civil wars he fought. And what about the Hellenistic faith? Without him to persecute them what will they do?
There would be changes, certainly but not necessarily overwhelmingly good or bad for Romania.How will a victory here change the empire?
Theodosius would probably remain in western Romania ITTL, which could turn problematic as ERE was in a period of relative decline ITTL : Valens wasn't particularly competent and allowing him to be victorious could mean that the efficient Theodosian reforms wouldn't be enacted or less so than IOTL and it wouldn't butterfly away rebellions and civil wars in Romania. Maxim the Great is still likely to revolt against Gratian ITTL, as his power and rise came from unrelated events and process.If Theodosius doesn’t come to the throne then the empire won’t have to deal with the civil wars he fought.
At this point, Imperial Christianism is triumphant : Gratian underwent a strong religious policy all the same. The big change is that Valens is still likely to favor Homeism in ERE. But Paganism and its upper class forms would likely still be more and more cloisoned, even without a Theodosius to turn a blind eye to the clerical offensive from Constantinople (and it would likely still happen ITTL in western Romania).And what about the Hellenistic faith? Without him to persecute them what will they do?
1. Christianity remains what it was OTL, both persecuting pagans and heretics. ITTL, the Copts and other Monophysites might well welcome the Muslims
With a PoD in late IVth century, it's likely that Islam might be simply butterflied away.2. A tolerant Christian emperor takes the throne and heals the rifts between Orthodox Christians and Monophysites.
Goths weren't as much Arians than Homeans (which, to make it simple, was a non-dogmatic semi-Arianism). They first converted to this half-Nicean Christianity because the eastern imperial court did supported it until Theodosian's reign; but they kept it until the VIIth century because it became an identitarian marker to differentiate themselves from Romans as there was an harder time making the difference in the late IVth and Vth centuries between Barbarians and Romans unless on a political level. Some peoples, as Burgundians, even switched from Nicean to Homean faith in the period for these reasons.However, such tolerance will make it easier to assimilate the Goths and other Arians.
With a PoD in late IVth century, it's likely that Islam might be simply butterflied away.
Actually, the Roman empire did if indirectly : while Christianities (orthodox as heterodox) managed to reach Arabia mostly from trade roads and undirect influence from eastern Romania and Ethiopia; Romans still had a vested interest on anything that touched borders with Persia.Why would it be? Rome wasn't really projecting power into Arabia
You had a generalized monotheistic presence in Arabia, while it wasn't always polity-supported as in Ethiopia and dependencies, or Himyar : between Niceans, Nazoreans, Nestorians, Monophysits,etc. communities, Christianism was a present feature on which Islam not only built upon, but directly came out from.as the Kingdom of Himyar shows there was already the monotheistic presence in Arabia that Islam built upon.