Once the Mongols were unified under his rule, Genghis Khan set about reshaping the clans into a real nation. There would be no more petty quarrels and stealing from one another, or jockeying for power, and the Mongols even stopped using the old clan names that had indicated divisions. Instead, Mongols were to be loyal only to him [source: Bawden].
Genghis Khan also set about building a well-equipped, disciplined fighting force that was capable of venturing outside Mongolia to conquer other lands. At the top, he appointed generals who were loyal to him, some of whom were his own sons [source: Bawden]. Under them, the Mongol warriors were organized into small units of 10, all of whom were responsible for one another. If one of them failed, they all were punished for the failure [source: Field Museum].
The heart of Genghis Khan's army was his cavalry units. They were composed of skilled Mongol horsemen, who rode sturdy, grass-fed steeds that could live off the land [source: Bawden]. They were outfitted with armor made of lightweight, flexible chain mail or leather plates, to allow them a fuller range of movement than more heavily armored opponents. They were armed with bows capable of shooting flaming or armor-piercing arrows up to 350 yards (320 meters), and small, light sabers that could be easily manipulated with one hand to cut and slash. Another ingenious Mongol weapon, a hooked lance, allowed them to drag an adversary off his horse [source: Field Museum].
Genghis Khan's forces also developed sophisticated tactics and strategy. Before they attacked an enemy army or besieged a city, they often spent months scouting their opponent's defenses, mapping roads and gathering intelligence about supply sources and escape routes. They also developed a communication network in which riders brought messages to relay stations, so that generals got information quickly. Once they went into battle, they used hit-and-run attacks and subterfuge to negate an enemy's numerical superiority. One favorite trick was for cavalry units to fake a retreat to get an opposing army to pursue them — and then suddenly turn back and go on the attack [source: Field Museum].
But Genghis Khan also realized that the hit-and-run tactics that the Mongols used so effectively wouldn't be enough to conquer a fortified city. So he also amassed weapons such as catapults and ladders to conduct sieges [source: Bawden]. Their ferocious attacks often left cities in ruins [source: Field Museum].