The ancient ruler of the Mongol Empire who significantly expanded its territory was Genghis Khan. Born as Temujin around 1162, he united the Mongolian tribes and founded the Mongol Empire in the early 13th century, promoting military strategies and organizational skills that enabled rapid conquest across Asia and into Europe. His reign marked the largest contiguous empire in history at its peak. Genghis Khan also implemented significant administrative reforms and encouraged trade along the Silk Road, fostering cultural exchanges. His legacy is both celebrated and scrutinized, as he is viewed as a unifier and a brutal conqueror.