Emergency situation:
Gurevians report a suspicious mongol movement. The army was small, but Peter ordered all units to move towards Gurev. Samarquand was near.
Mongols concentrated a large army. It was clear they would invade the next days! The army was large and Mongols are really tough at war. Our generals estimated that we may lose the siege of Gurev. This would be disastrous, because we had no more army.
At first Peter was socked and terrified. After an afternoon of calm thinking he decided what he needed to do. Although he had already requested an urgent meeting of the royal council, he skipped it and start ordering.
Peter decided to leave Gurev alone. Gurevian forces refused to leave. So a battalion stayed back. Peter promised that he will liberate them soon. All the other army retreated to Caricyn.
We need more army and fast. Peter decided to declare emergency. Lower class citizents were forced to work harder. All cities were ordered to train units, mainly cavalry, because it moves fast. Workers worked only to support the war effort (cut trees). This caused a period of anarchy, but Mongolian army was too strong and Peter couldn't let this on luck.
As expected Mongols attacked. Russians prayed to god to help them and show mercy. The next day battle begun!
Loss of Gurev:
Gurevians defended heroically their city. They lost, but they damaged the invaders giving Russia the needed time to prepare appropriately.
External (non) help:
French army was near. Peter asked France for help, but they didn't help us.
China could surprise Mongols in the far east. However, they didn't help us too. Russians had to fight this war alone.
Second battle of Kazan:
Some mongols battalions moved towards Kazan. Russians managed to kill them all except a weak crossbow.
Not military events:
Peter ordered and funded extended espionage against Mongols.
People died of exhaustion supporting the war effort. Mainly in Sankt-Peteburg, Kiev, Uglish, Krasnodar, even Moskva!
Wars started in western Europe. People questioned papacy at last. This event was good for Russia, because no western state would declare war in Russia now.
Battle of Gurev:
Our army concentrated in Caricyn and marched to Gurev. In a historical battle that is still studied in modern wars academies the Russian army managed something amazing. They killed all mongols units losing only 2 out of 18 battalions, while our generalsestimated the chances of success between 49% and 65%.
Collapse of Mongol empire:
The loss of Gurev was devastating for Mongols. Mongols lost over one fourth of their army in just one month. Warlords of Kublai Khan revolted against him. The mongol empire collapsed. However, Kublai fleed to his capital and regained some control over Mongolia.
Russia started to go back to its ordinary condition. Longbowmans moved back to their homes to clam down the worried citizents.
Russia survived again the mongol invasion paying a harse price, but the war wasn't over yet. Mongol state was collapsing but still too strong for Russia.
Our generals estimated that there wasn't any mongol army near us. So the emergency could end. Our citizents celebrated the end of the war. The tsardom needed some years to come back to its normal state, but after all it was a great celebration.
The war ended formally in 1459AD. This time the terms were opposite and Mongols paid war compensations. It was the first time in history Mongols paid war compensations.
Yuan dynasty controlled northern china. South China was controlled by a chinese dynasty, the Ming. Mongol warlords declared indepedence from Yuan and continue the never-ending wars between them. Timur declared indepedence in Samarquand and the Ilkhanate was formed in Persia. Golden Horde was massacred by us.
According to our spies the Yuan dynasty had a large army. However, their units were less powerful than our cavalry.