In 1206, at a grand assembly by the Onon River, Temüjin was proclaimed Genghis Khan, a title with debated origins—some say it signifies strength or universal rule, while others argue it meant little more than a break from traditional titles. Now ruling over a million people, Genghis Khan initiated a social overhaul to dismantle tribal loyalties, favoring allegiance solely to him and his family, thus forming a centralized state. Traditional tribal leaders were mostly gone, allowing Genghis to elevate his family as the 'Golden Family' atop the social structure, with a new aristocracy and loyal families beneath.

Genghis restructured Mongol society into a military decimal system, drafting men aged fifteen to seventy into units of a thousand, further divided into hundreds and tens. This structure also incorporated families, effectively blending military and societal functions to ensure loyalty directly to Genghis and prevent tribal uprisings.

Senior commanders, or nökod, like Bo'orchu and Muqali, were appointed significant military roles, showcasing Genghis's meritocratic approach. Even those from humble origins were given command, demonstrating Genghis’s emphasis on loyalty and merit over birthright. Some commanders were allowed to maintain their tribal identities, a concession for their loyalty.

Additionally, the expansion of the keshig, the khan's bodyguard, played a crucial role. Initially a small guard, its numbers swelled to 10,000, serving various roles from personal protection to administration, and acting as a training ground for future leaders. This elite group enjoyed privileges and direct access to Genghis Khan, securing their loyalty and grooming them for higher command.