To Yivali:
Well, you are wrong - they are both camels. The one-humped one is, correctly, dromedary which is remains today only as domesticated, while the two-humped one is called Bactrian and can be sometimes met in wild. Mostly in Middle Asia deserts, as it name suggests (Bactria was a country somewhat to the east of Caspian Sea). They are different species of the same genus. Also, Bactrians are MORE OFTEN used as beasts of burden, while Dromedaries are MORE OFTEN used as mounts. However, this isn't law & they are mostly interchangeble. Quality is often more important - best riding camels can run faster than horses, while worst... but quality of caravaneers is even more important in such cases.
And you can look some historical information either at the beginning of this thread or in one called somewhat like "1001 nights"...
To Aezeal:
Considering prince of Persia - remember that before Mohammed limited Muslims to 4 wives, harems in the region could get really big.
So such princes could (& did) often be fielded by regiments!
Do you offer to make them a troop type?