Sartaq Khan is an interesting figure in the history of the Mongol Empire, most notable for the fact that he was Christian (most likely Nestorian but possibly also Orthodox). In 1256 he succeeded Batu Khan as leader of the Golden Horde, but his reign was short lived, dying later that year, likely poisoned by his Muslim Uncles Berke and Berkhchir. He was succeeded by Ulaghch, who died a year later in 1257, leading to Berke, Sartaq's uncle, to take the throne and establish Islam as the dominant religion in the Golden Horde. A few years later the
Mongol Empire would begin to fracture following the death of Möngke Khan in 1259, resulting in its constituent Khanates effectively becoming independent.
What if Sartaq survives the assassination attempt, eliminates his treacherous Uncles and is able to consolidate his rule and establish Christianity in the Golden Horde in time for the disintegration of the Mongol Empire?
Would Nestorian Christianity gain a significant stronghold in Eastern Europe, or would Sartaq convert to either the Orthodox or Catholic Churches to gain foreign support?
There were still Pagan holdouts in Lithuania at this time. Would a Christian Golden Horde get involved in the
Northern Crusades, and what will the long-term consequences be, especially given OTL Golden Horde incursions into Poland and Lithuania and the
Great Prussian Uprising in 1260?
How will this affect the balance of power in the Middle East. IOTL Berke formed an alliance with the Mamluks against the Ilkhanate, but with him out of the way and a Christian in charge of the horde, might the proposed
Franco-Mongol alliance work out ITTL? Will this lead to the Crusader States holding out, or even expanding with Mongol assistance?
I would also appreciate it if people could point me in the direction of any useful sources that deal with this particular era, as I might want to expand this into a more developed timeline later on.