@Russian sorry about that. These are the forums where we've been discussing the timeline: (
https://www.alternatehistory.com/fo...-of-north-america.422086/page-2#post-15426213) and (
https://www.alternatehistory.com/forum/threads/how-high-can-we-get-the-world-population.421571/) and (
https://www.alternatehistory.com/forum/threads/kievan-rus-reunified.420829/)
To sum up the timeline so far the Mongols are defeated at the Battle of Badger Mouth. The Mongols lose many troops. Muquali and Ogedei Khan are killed. Jin reinforces their border at Zhangjiakou and the other passes through the great wall. The weakened Mongols continue their campaign westwards. During the invasion Europe the Mongols manage to get as far as northern France. Horse archery worked well in wide open spaces but in the dense forest of 1200's France the Mongol horse archers did not work as well. Using this to their advantage, the French managed in inflict a crippling defeat on the Mongols. Emboldened by this victory the other nations in Europe which had surrendered to the Mongols revolted and attacked the Mongols. During their retreat out of Europe the Golden Horde suffered savage losses (their numbers at that point were down to about 12-15% of what they had prior to the Battle of Badger Mouth) and began a retreat back to Central Asia. Jin and Song became threatened when they learned exactly what the Golden Horde had been up to and how far they had conquered. Jin and Song separately began attacks on the Mongols and shattered what's left of the Golden Horde.
Bit of a misunderstanding about when the conquests were. I meant that there are no Mongol invasions of anywhere outside Central Asia after 1241. This means that no invasions of the Middle East occur, such as the Mongol takeover of the Sultanate of Rum. The Abbasid Empire is untouched by the Mongols and presumably lasts for a bit longer. The great library of Baghdad is still intact and the destruction of the irrigation canals is avoided. Because the Eastern Europeans no longer have to deal with the Mongols after 1241 the rise of Moscow has been butterflied away.
The Song go on to start exploring the world in the 1200's in preparation for a circumnavigation attempt. They make contact with Central American civilizations and start trade, bringing technology to them and spreading potatoes from Peru to the entire world, boosting the entire world's population significantly. Song explores northwards and discovers the peoples of Siberia. Trade with these peoples results in technological exchange and by the 1400's there's trade flowing into Europe across the Volga from various Siberian Kingdoms. When the trade routes to Europe through the Middle East are cut (the nations there won't let western traders travel through), trade to China simply diverts across the Volga river through territory already mapped by the native Siberian Kingdoms.
by the late 1300's most civilizations in the Americas, Africa, South East Asia and Asia have guns and tech approaching what China has. By the 1400's the Siberians achieve this. There is a global trade network in place by the 1300's allowing exchange of technology and ideas. If the Byzantine Empire can survive in this scenario to the 1400's then ships from the global trade network will start arriving in ports around the Mediterranean Sea. Those ships might not be too useful however as the powers of the Middle East could be attached to the same trade network.
In Europe the Reconquista takes back the entire Iberian Peninsula. Due to butterflies radiating out from the POD at the Battle of Badger mouth at the speed of human interaction we can assume that many major people in Europe have been butterflied out of existence. Michael VIII Palaigolos for example is never born. The ERE Emperors in this timeline did manage to retake some of the land conquered by the crusaders in the Fourth Crusade. My current draft has the Empire of Nicaea taking the Latin Empire, the Empire of Thessalonica then by the mid 1300's absorbing the Empire of Trebizond. At that point they focus their efforts on the Sultanate of Rum, which has until that point been attempting to expand into the Abbasid Empire and the Ayyubid Sultanate. Does the ERE expanding this much sound likely or if not how far would they get? Would it be the Despotate of Epirus or the Empire of Nicea be the one to reunify the ERE?
If the opportunity arises in that timeline's Reconquista the ERE might temporarily delay an attack on Rum to "help out" Spain in the Reconquista. As part of this effort they could take and establish forts on both sides of the Strait of Gibraltar. The condition for their help is that they can be granted control of these forts. By taxing ships passing through the strait the ERE could secure another source of income. They offer to pay a percentage of the profits from these forts as rent and in exchange the ERE will pay for the upkeep and defense of these facilities which should discourage any further attacks into the Iberian Peninsula from North Africa.
Since Eastern Europe is now in a stronger position would they even have the capability to significantly help the ERE? Would the Eastern Roman Empire even be willing to call for assistance from any of the nations there? Once an Eastern European nation gets a trade route to China running through it, would that be enough to allow a reunification of the Kievan Rus? I imagine that such a route might go through the south of the Volga. The nations of Eastern Europe, realizing how valuable it was might move to take control of the point where the trade route crosses the river. Whomever can control that point for a prolonged period of time may have a serious advantage over the rest of Eastern Europe. Which of the nations might be able to win such a conflict?
Sometime in the 1400's the HRE observes the conflict in the south of the Volga and realizes that unification of the Kievan Rus is now a possibility. With this threat looming on the horizon would this be enough for the states of the HRE to start ceding more power to the Holy Roman Emperor and beginning a process of having people identify not as part of their state or town, but foremost as citizens of the HRE?
Because the trade route from Europe to China has diverted through Eastern Europe, Eastern Europe is now a high priority target for any power that can topple the ERE. Central Europe (as in OTL) is also a potential target for such powers (Battle of Vienna). With both Vienna and Kiev in particular becoming targets of any power defeating the ERE would we see the HRE and Eastern Europe helping the ERE in order to use them as a buffer? Would it be plausible for them to think in such a way and realize this threat? If so, would the states of Eastern Europe even have the power to influence the expansion of the ERE in any way?
About saying Central Europe. That was a typo. Good catch Russian. I've fixed the post.
@The Merovingian I've added quite a bit more info. Sorry about the long post.
I'm new to Alternate History so I would appreciate any feedback and suggestions for improvement.