Alternatively for another scenario that amounts to also screwing Moscow, what if the Mongol invasions fail to eliminate Moscow's original Russian 'parent' state Vladimir-Suzdal and Moscow does not get the chance to become the dominant state of NE Russia? Moscow (founded 1147?) was only a minor town in the C12th, as part of the then dominant V-S conglomerate and with no stronger chances of breaking away and dominating the region if the the main state failed than other local rivals such as Ryazan and Nizhni Novgorod (both of whom had greater commercial prospects as on larger rivers).Even after the Mongol invasion and destruction of the main V-S army and killing of its leadership in March 1238, followed by the sack of Vladimir, the town of Moscow was merely an appanage principality of the 'Great Principality' of V-S, ruled by Daniel, a younger son of Alexander Nevsky (ruling prince of the mercantile city of Novgorod as of 1238-40 but from the royal house of Vladimir-Suzdal) who emerged as the new leader of V-S after his elder brothers in the 1250s but died early in 1263.
Until the ruinous civil wars over Vladimir-Suzdal of Daniel's elder brothers in the later C13th finished off its precarious prosperity as a Mongol vassal state and Moscow and Tver then emerged as rivals to seize power after 1300, Moscow was hardly a major player. It only emerged as a the main heir of V-S under Ivan 'Kalita' ('Moneybags') in the 1330s as the Mongols' trusted tax-collectors, due to Ivan's political genius and the eclipse of Tver (a larger and older city so then seen as a likelier winner) when its ruler (St) Mikhail was executed by the Mongols in 1318. Even after that, the early death of Ivan in 1340, the weakness of his sons, the long regency for his grandson Dmitri Donskoy, the losses caused by the Black Death, and the sack of Moscow by Khan Toktamish in 1382 could have halted Moscow's rise and revived Tver or passed the political leadership to Nizhni Novgorod or a still prosperous Novgorod (the latter being safer from Mongol attack as far to the NW in marshland and bolstered by Baltic trade). Smolensk was unlikely to succeed as too near the Lithuanian frontier so open to attack by them if seen as a threat, ditto Ryazan (and the Mongols or the Crimean Khans could sack the latter). And if the refugee Patriarch from Kiev does not choose to settle in Moscow in the mid-C14th but heads to a stronger, older and holier Vladimir with its great cathedrals, 'Holy Moscow' is less prestigious.
So what if the Mongol attack on NE Russia goes wrong in 1238 and Vladimir survives as a major urban centre and base for stability and trade, with its southern rivals (principally Kiev and Chernigov) sacked and Lithuania expanding E into Smolensk? Given the huge size and advanced weaponry of the Mongol army, the only realistic chances for its retreat in 1238 would be either an epidemic in the ranks (eg food-poisoning or drinking from a polluted river), which the Russians could then play up as a 'miracle' aided by the holy icons of Vladimir, or the Mongol leadership facing a stronger and earlier threat of intervention from Poland than reality - as requested in person by the Russian rulers of Kiev? - and deciding to crush this quickly instead of wasting time on Vladimir. Perhaps the strongest and wisest of the bickering southern Russian rulers, Daniel of Galicia-Volynia (1201-64), is already ruler in Kiev (which in OTL he did not acquire until the Mongols were nearing the city in 1240) and realises that the huge size of the Mongol army means an even greater disaster than Russia suffered in the earlier raids around 1220 and/or has been warned by a spy in the Mongol army that their attack is aimed at all Russia then Poland and Hungary in 'world conquest' mode . He alerts the Poles to this in 1238-9 to get a joint army assembled. This is duly overwhelmed , but the Mongols have had to hurry SW to Kiev so Vladimir survives the 1238 campaign and once Kiev has fallen its ruler (either a surviving Yuri II, killed in 1238 in OTL, or his younger brother Yaroslav) prudently pays tribute. Once the Great Khan Ogodai dies the Mongols give up their major invasions and stick to extorting tribute and settling on the lower Don and Volga, as in OTL.
That way, Vladimir survives as the centre of power and commerce in a relatively undamaged NE Russia, and with its C12th prestige intact only its feuding royal family and dodgy successions weaken it. It is also strong enough to hold back the Lithuanians, provided that it avoids annoying the Mongols by paying up whatever they require on time until the Golden Horde's power fails in the later C14th and early C15th. The Patriarchs move to Vladimir, Alexander Nevsky does not die at c.43 in 1263 but has a long and successful reign in Vladimir into his 60s and is succeeded by one equally competent and unchallenged son, and Moscow is only a junior principality ruled by younger sons like Tver. At best, Moscow's strategic position makes it a useful second-ranking city. And if we then get a competent military leader like Dmitri Donskoy based in Vladimir ruling a larger state that has avoided the Black Death due to its remoteness and hires some European knights to help overhaul its army , could Vladimir then defeat the Golden Horde more heavily than Dmitri did in OTL in 1380 and take over Kazan and the upper Volga/ Urals fur trade around 1400-40? That way we have Vladimir as the centre of a surviving 'Great Principality' , albeit with a danger of the Russian elite continuing the established practice of multiple inheritance and dividing and weakening the state - and acquiring a Byzantine imperial bride and imperial pretensions plus a useful vassal-army of Volga Mongol tribes to turn on Poland-Lithuania in the C15th?
