1. The Mongols were nomadic tribes from eastern Asia that were unified under Genghis Khan in the early 13th century. 2. Genghis Khan and his descendants used innovative military tactics and technology to build a vast empire stretching from Eastern Europe to East Asia by the late 13th century. 3. The Mongol Empire promoted trade and stability along the Silk Road during this period but decline set in after the death of later khans due to the empire's vast size and diversity.