Final answer:
The Mongols' rise to power was significantly influenced by Genghis Khan's unification of the tribes and strategic military conquests, creating a vast empire known for its highly disciplined cavalry and innovative siege tactics.
Step-by-step explanation:
A key factor in the Mongols' rise to power was the leadership of Genghis Khan, who united the feuding Mongolian tribes and embarked on a series of conquests that formed the largest contiguous empire in history. His military strategies, utilization of sophisticated siege techniques, and creation of a highly disciplined cavalry allowed the Mongols to rapidly expand their territory across Asia and into Europe. The empire amassed wealth and changed in character, becoming more materialistic and sophisticated in warfare under Genghis Khan's rule. However, after his death, the empire struggled to maintain unity, facing rivalries and divisions among his successors.