The ultimate soldier......as The Cubster said: The Mongols
I would have gone for the spartans - strict regime/training etc moulded into ultimate fighters but what territory did they conquer?
The mongols were born that tough. Their lifestyle, the conditions, their tactics and ability to absorb the latest technology. Riding 120 miles in a day? living off the blood of their mounts? The 'cold face' ?
They were the best warriors in the world, only they didn't know it until Temujin told them...


