In our scenario, Ogedei Khan doesn't die in 1241, which allows the Mongols to retain their unity and continue their incursions into Europe and Middle East. In 1245, the Mongols under the leadership of Batu Khan invade central Europe leading to the intense battles in medieval Bohemia. At the battle of Olomouc in 1246, the allied armies of the Holy Roman Empire attempted to stop the Mongol invasion.

The defeat here didn't stop the Mongols who were now full of wrath. And although the Europeans were now preparing a Crusade, this wrath will bring them to Bohemia and the siege of Prague will make things even worse. At the same time, a group of Mongols led by Batu Khan moved south to attack Italy and sacked Rome. To the north the armies of Subotai and Kadan were invading Germany and moving towards France, leading to the battles of Lubeck and Fulda Gap against the alliance created by Emperor Wenceslaus and King of France Louis IX.