Final answer:
The Mongols established a large empire between 1206 and 1280 through superior military organization, tactics, and integrating foreign soldiers and leaders. Genghis Khan effectively unified the Mongol tribes and they encouraged trade and communication across the empire during the Pax Mongolica.
Step-by-step explanation:
The Mongols created a large empire between 1206 and 1280 A.D. mainly through superior organization and military tactics. Their army, comprised entirely of cavalry, was fast, disciplined, and excelled at siege warfare. They effectively used surprise tactics and psychological warfare to strike terror into their enemies. Moreover, Genghis Khan's leadership unified the Mongol tribes and focused their efforts on conquest. Their success was also partly due to their pragmatism; they included foreign leaders and soldiers into their ranks, utilized the knowledge of those they conquered, and were strategic about who and where they attacked.
They did not create new forms of government and religion, nor did they only fight weak and powerless countries—many of their opponents were strong and well-established civilizations. Instead, they established a reputation for mercilessness, but also for encouraging trade and communication across their empire, which played a significant role in their ability to maintain control over such vast territories. The era of relative peace and stability they imposed, known as the Pax Mongolica, facilitated an unprecedented exchange of ideas, goods, and technologies.