The mongols invaded others land because of three main reasons Ecology, trade distribution and Chinggis Khan
Ecology:In 1180-120, Mongolia experienced a drop in the annual temperature mean. Growing season were cut short. Less grass meant a real danger to the mongols animals. Without grass there would be no animals, without animals there would be no food for the mongols. Which could had lead to the invasion of other lands.
Trade distribution: China reduced on trade with the mongols. The mongols depended on trade for goods that they needed the response due to them unable to obtain food was invasion. So they could obtain more food.
Chinggis Khan: Sky gods gave Khan the mission to take control of the world. Which could had lead Chinngis to lead his army into conquering other land.
Ecology:In 1180-120, Mongolia experienced a drop in the annual temperature mean. Growing season were cut short. Less grass meant a real danger to the mongols animals. Without grass there would be no animals, without animals there would be no food for the mongols. Which could had lead to the invasion of other lands.
Trade distribution: China reduced on trade with the mongols. The mongols depended on trade for goods that they needed the response due to them unable to obtain food was invasion. So they could obtain more food.
Chinggis Khan: Sky gods gave Khan the mission to take control of the world. Which could had lead Chinngis to lead his army into conquering other land.