Genghis Khan united the Mongol tribes in 1206. That year, Temüjin’s final victories and alliances brought the major tribes of the Mongolian Plateau under his authority, and a great assembly acclaimed him as Genghis Khan.
The unification was the result of decades of warfare, diplomacy, marriage alliances, and political reorganization. Temüjin defeated or absorbed rivals including the Tatars, Merkits, Keraites, and Naimans. He also rewarded loyalty based increasingly on personal service rather than only tribal lineage, helping create a more centralized military state.
At the 1206 assembly, often called a kurultai, the newly unified nation was reorganized into military and administrative units. Genghis Khan distributed commands and territories among members of his family and trusted companions, laying foundations for the later Mongol Empire.
The date is sometimes confused with 1211, when the Mongols launched a major invasion of the Jin dynasty, or 1227, the year Genghis Khan died. The key event in 1206 was political unification and his elevation as supreme khan, not the completion of all later conquests.