On creating your own Mongol horde....

     The Great Khan has had twenty-two sons by his four legitimate wives, the eldest of whom, named Chinghis, was designed to inherit the government of the empire; and this nomination was confirmed by him during the life-time of his father.  But, as it came to pass he died and left a son, whose name is Themur.  He, as the representative of his father, is to succeed to the dominion.  The disposition of this prince is good, and he is endowed with wisdom and valour;  of the latter he has given proofs in several successful battles.
     Besides these, his majesty has twenty-five sons by his concubines, all of them brave soldiers, having been continually employed in the military profession.  These he has placed in the rank of nobles.  Of his legitimate sons, seven are at the head of extensive provinces and kingdoms, which they govern with wisdom and prudence, as might be expected of the children of one whose great qualities have not been surpassed, in the general estimation, by any person of the Tartar race.

-The Travels of Marco Polo, from his chapter on Kublai Khan