Summarize the development and impact of the mongol empire in the period 1200-1450

The year 1206, when Temüjin, son of Yesügei, was elected Genghis Khan of a federation of tribes on the banks of the Onon River, must be regarded as the beginning of the Mongol empire. This federation not only consisted of Mongols in the proper sense—that is, Mongol-speaking tribes—but also included tribes of Turkish descent. Before 1206 Genghis Khan was but one of the tribal leaders fighting for supremacy in the steppe regions south and southeast of Lake Baikal; his victories over the Kereit and then the Naiman Turks, however, gave him undisputed authority over the whole of what is now Mongolia.