Radically changing the world's religious landscape without butterflying away Islam

[Kyro92]

I've been pondering this over the past few days. It's trivially obvious to posit a world in which Muhammad has born, or to go earlier that and have the non-founding of Christianity as your POD.

But how much could the layout of world religions be altered in a world in which still saw the founding of Islam and the expansion of the caliphate?

Right off the bat, this limits us to a POD in the late 6th century or later, as any earlier then would butterfly away Muhammad's conception.

The best idea I can come up with for the Sassanid campaign against the Byzantines to be more successful, culminating in the capture or Heraclius, and the exhausted Byzantine Empire splintering with rival claimants to the throne. Khosraw would then march on Constantinople with Heraclius in tow, and an offer of peace- reinstate Heraclius, accept the loss of territory and status as a vassal of Persia. Constantinople, exhausted by war and cut off from revenue and trade due to the civil war, accepts...

Of course, Khosraw could then honour the deal. But let's say that he instead decides to end the thorn in Persia's side once and for all and do to them as the Romans did to Carthage

And, just because it's poetic, let's say that just as Constantinople is being sacked the Arabic invasion begins, striking at the largely undefended and unprepared Ctephison whilst the bull of the Persian armies are far to the West.

 

[EasternRomanEmpire]

I've been pondering this over the past few days. It's trivially obvious to posit a world in which Muhammad has born, or to go earlier that and have the non-founding of Christianity as your POD.

But how much could the layout of world religions be altered in a world in which still saw the founding of Islam and the expansion of the caliphate?

Right off the bat, this limits us to a POD in the late 6th century or later, as any earlier then would butterfly away Muhammad's conception.

The best idea I can come up with for the Sassanid campaign against the Byzantines to be more successful, culminating in the capture or Heraclius, and the exhausted Byzantine Empire splintering with rival claimants to the throne. Khosraw would then march on Constantinople with Heraclius in tow, and an offer of peace- reinstate Heraclius, accept the loss of territory and status as a vassal of Persia. Constantinople, exhausted by war and cut off from revenue and trade due to the civil war, accepts...

Of course, Khosraw could then honour the deal. But let's say that he instead decides to end the thorn in Persia's side once and for all and do to them as the Romans did to Carthage

And, just because it's poetic, let's say that just as Constantinople is being sacked the Arabic invasion begins, striking at the largely undefended and unprepared Ctephison whilst the bull of the Persian armies are far to the West.

The Sassanids can't take Constantinople, they didn't have a significant navy in the Med at all unlike the Arabs who still failed; which is precisely why Persia cannot win, they're also exhausted and any attempts at a quick end to the war will fail. Even if the Sassanids capture Heraclius around that point they were very unlikely to win and the ERE won't be in a civil war for that long, Heraclius himself arrived in power after a civil war and it didn't prevent him from winning against Persia who is as exhausted as the ERE.

 

[Arkenfolm]

Depends how much you want the Caliphate to expand. If it doesn't expand enough, then it's very likely that whatever "Islam" looks like barely resembles Islam as we know it.

I think the big one is preventing the Islamic conquest of Central Asia, because that butterflies the Islamisation of the Turks (and maybe even a lot of the Turkicisation of that region) and keeps a very religiously diverse region intact. It's pretty unlikely that a non-Islamic conquerer (unless they were Christian) would replicate the actions of Timur and permanently end whatever remained of the various religions there.

If you have different Turkic tribes, then it's possible that the Arabs lose Persia and the new Turko-Persian state there opts for Manichaeism since that was popular among some groups of Turks. Or Buddhism, but I find that a little less interesting since there already are many Buddhist states OTL but only a single Manichaean state.