Joint Crusade/Jihad against an non Abrahamic/Anti-Abrahamic threat?

[DUWANG]

While there were many crusades against the ummah and many jihads against Christendom, there will still through out still many enough on both sides through history who viewed each other from branching from the same tree.
Whenever you were an Eastern Roman monk writing about the new heretic sect from Arabia or an Andalusian Imam writing about the fellow followers of the book who fell for lies.

Now I just had an idea in mind about if we could have a scenario post the Umayyad Caliphate where we could see a large number of Christian and Islamic states banding together to defend/fight against an non Abrahamic enemy? It could be outside or inside the Abrahamic world. Perhaps a large heathen nation, like a steppe people from Central Asia, or perhaps a powerful individual inside, who one day went insane and proclaimed himself the Antichrist/Dajjal.

Are there any ways where an outside force could be strong enough and simply so despicable in their practice that both Muslim and Christian lords not only politically but also for religious reasons join hands?
That seems more likely than a Muslim or Christian lord close enough to both declaring himself to the personification of evil and have enough power to get the attention of both sides before being ripped apart by literally anyone else living in said lands.

 

[Polish Eagle]

Frederick Barbarossa might be the most plausible candidate, actually, given his bad relations with the Papacy--though it's hard to imagine a scenario where he doesn't patch things up with Rome if there's a prominent Jihad against him.

Central Asian steppe peoples are unlikely, though. The Christian conviction that the kingdom of Prestor John was somewhere out there and that the Mongols and their neighbors might have large numbers of Christians among them will make a crusade unlikely. Unless maybe you get a Manichean horde? Or a Bogumil one? Another outbreak of Bogumilism might antagonize the Turks and the Christians both in the 15th century.

Finally, there's the "Sunset Invasion" scenario--Aztec invaders and their human sacrifices will be a target for both the Spanish kingdoms and their Moorish neighbors. Not particularly likely, though.

Any such joint crusade/jihad would, though, be a coincidental affair rather than high-level cooperation we saw against Napoleon and during the World Wars. Both forces just happening to have the same enemy and maybe agreeing not to mess with one another rather than actually working together--allying with heretics would be a bridge too far.

 

[CountofDooku]

Zoroastrianist Persia maybe if it is mroe powerful and a threat to the Cristian and Muslim world? Maybe taking the place of Byzantium and the later Ottoman Empire?

 

[Lalli]

Taking how much Christians and Muslims hated even other Christians and Muslims who didn't follow the faith correctly, I see this unlikely without some extremely serious threat. And geography too would bring some limit. Europeans hardly are very intrested about India or East Asia enough to begin war and Americas hardly intrest Muslims. So perhaps if Mongols are felt so big threat that some Christian and Muslim nations make temporary alliance.

 

[GameBawesome]

Zoroastrianist Persia maybe if it is mroe powerful and a threat to the Cristian and Muslim world? Maybe taking the place of Byzantium and the later Ottoman Empire?

There is one plausible candidate for that: The Ziyarid Dynasty was originally Zoroastrian under its first leader, Mardavij. He sought to restore Zoroastrism in Iran and create a new Persian empire, but he was assassinated and his heirs converted to Islam.

So, you would need to wank Mardavji’s Ziyarid Dynasty, to be powerful enough to be a threat to the Levant

 

[Arkenfolm]

Central Asian steppe peoples are unlikely, though. The Christian conviction that the kingdom of Prestor John was somewhere out there and that the Mongols and their neighbors might have large numbers of Christians among them will make a crusade unlikely. Unless maybe you get a Manichean horde? Or a Bogumil one? Another outbreak of Bogumilism might antagonize the Turks and the Christians both in the 15th century.

The Prester John legend was dying quickly in the 13th century, and the common perception thanks to Mongol invasions in Hungary and Poland was that they were soldiers of Gog and Magog (Europeans even believed the word "Mongol" came from Magog) set free as a prelude to the end of the world. The Christians among them were usually dismissed as schismatics and heretics. Opinions only changed in the late 13th century because the Mongols weren't causing AS much trouble against Catholic nations and because they shared a mutual enemy in the Mamluks.

I think you'd need the Crusader States to do a little better in the late 13th century or have them be re-established by a joint Ilkhanate-Crusader operation in the 1299-1303 war which proves successful (and IMO there's a good chance for it if the Mamluks are fighting on two fronts). Then just let relations collapse between the two, which it will because in no world will Muslim Ilkhans like Ghazan or Oljeitu hand Jerusalem to the Crusaders. At some point, the Crusaders will probably want an alliance with the Mamluks. I expect the Mamluks at this point would be rather fucked politically, so one candidate for their throne could be pro-European in the name of obtaining trade with the Italians and retaking at least part of the Holy Land. And they still have the Abbasid caliph under their control, so there you go--a joint Crusade/Jihad against the Ilkhans. Perhaps they'd pick and choose regarding Ibn Taymiyya's fatwas, such as his condemnation of the Ilkhanate and all Muslims who followed them as apostates due to their adherence to traditional Mongol law and religious tolerance, and conveniently ignore his stance toward Christians.

Some of the Anatolian beyliks might join as well, since they were constantly under threat from the Ilkhans and had reason to want to permanently end the remnants of the Sultanate of Rum that still persisted.

 

[Atrahasis]

An idea that came to my mind a while ago is an Abassid-Byzantine alliance against the Mongols in a world where the Komnenian restoration succeeded. Like, the Mongols threaten both Anatolia and the Balkans, you could easily add Hungary and Poland that are also under a direct threat a have the pope make a crusading bull for the issue. If you have the Caliph being a more shrewd politician than al-Mustasim you could add the Shi'ites to the equation. So, in the best case you have the Orthodox Byzantine Empire; the Sunni Abassid caliphate; the Catholics Poland and Hungary, along with some western knights; and the Shi'ite Assassin order fighting together to stop the Mongol advance.

Another thing could be stronger crusader states allying with the Ayyubids instead of the Mongols, seeing them as a bigger threat.

 

[walmart]

There is only one holy war waged by two different religions against a third that is the 1857 sepoy mutiny

 

[naraic]

I can only find evidence of one crusader called by the church against the Mongols (1241 in Poland) but I can find evidence of multiple Jihad called against Mongols by different bodies.

If you line up a crusade against the Mongols in Europe happening at the same time that there is a jihad called against Mongols in a different time does it count as a joint crusade/jihad or simply two crusades/jihad happening in parallels.

 

[Byzantion]

It somehow happened, as being said before, during the Mongol invasions.
Maybe otherwise more powerful and widespread Pagan Viking invasions until 11th Century. Maybe an organised Norse (Germannic) war cult calli g fore eternal conquest and looting. Maybe even Spanish Emirates threatened by Norse invaders.