Final answer:
The Mongols relied on fast Mongolian horses, which were central to their highly mobile and skilled cavalry, enabling the creation of the world's largest contiguous land empire.
Step-by-step explanation:
The horse was the keystone that the Mongols used to build the greatest land empire in recorded history. These swift Mongolian horses, which offered the endurance, speed, and mobility required for the Mongol Empire's quick growth, were essential to the Mongol military strategy. The empire's founder, Genghis Khan, used their superior cavalry abilities to bring rival clans together and begin a string of extremely successful military victories. The Mongol Army, which was made up largely of horsemen with excellent archery and mobility skills, routed the weakly fortified regions of Eurasia. The practice of each soldier having access to many horses for constant movement and fighting helped with this mobility. These troops could also carry dried meat and milk their horses for food, eliminating the need for a supply train. Recruiting Chinese engineers, who taught them how to construct siege machines like catapults and trebuchets, improved their siege warfare capabilities.