The mongols at that time were in a crunch for resources. It is said that he was responsible for the murder of his brother when he was only 12 years old. This was reflected in the life of Temujin as well. These tribes were constantly infighting and where it kept them ready for war, it also weakened any effort to expand outwards into China or on towards the Adriatic Sea. Growing up, he fought and won over the other Mongolian tribes that were constantly at loggerheads with each other. Genghis Khan rose from complete anonymity and was orphaned at a young age. The impact of his rise and the expansion of the Mongol Empire in the 12th century is discussed, and felt, to this day.
The mention of Genghis Khan evokes images of war, carnage, and archers riding horses, raining death in the form of arrows.