Final answer:
After Temujin was elected as Genghis Khan in 1206, he established the Mongol Empire, united the Mongol tribes, and expanded his empire by conquering neighboring kingdoms.
Step-by-step explanation:
In 1206, after being elected Genghis Khan, Temujin established the Mongol Empire. He orchestrated the unification of the Mongol tribes and launched a series of conquests that would expand his empire substantially. This unification included the defeat of neighboring tribes and kingdoms such as the Tanguts, the Jurchen, and Qara Khitai between 1210 and 1218. The Mongol Empire grew to become the largest contiguous land empire in history, profoundly changing the course of world events. Under Genghis Khan's leadership, the empire also introduced a new law code, the yassa, and transformed the Mongolian military into a highly efficient war machine that dominated Eurasia.