These are an Old Peoples, the original occupants of Daletal. They have been displaced by the Humans into the back corners of The Six Lands and the Badlands. For generations they waited for a sign so they could take their revenge against the Humans. The Great One came and led them. They swarmed across The Six Lands and ruled! Then The Fall occured. Their numbers have been greatly reduced since the time of their vengence, the Time of Merideth. They have returned to their back corners of The Six Lands. They wait for the Return of the Great One.
The Sleeping King is a near mythic figure that has a presence in real history. Originally called the Lost King, he came from a Land to the East where he had been a King. He left his Land because he felt he had failed his people ( the details are vague upon this point). He arrived here to discover a land under the boot of Merideth the Great. He vowed that, “All people shall be free to live as they need to live. No one should live as a slave to a man or fear!” Thus he began to lead. From a small band came The Six Armies Who Were One. Upon the final assault on Merideth, he brought freedom to The Six Lands. Then left, vowing to return if needed.
This powerful and ruthless legendary leader amassed an army of Beastmen and mercenaries conquering most of The Six Lands. His rule was ruthless, treating the people of the lands as slaves. He took the resources he needed for his campaigns without regard for the “sheep” left behind. He oppressed the people for nearly two decades before being overthrown by the Six Armies who march as One and the Sleeping King.
One thing you must realise is that there is no such thing as pure iron/steel these days. Iron/steel isn't nearly as strong now as it was in medieval times. However, with that said, iron in early medieval times was so soft you could hack right through a helm with a sword and leave a nice lil mark on the skull (depending on the grade of iron used on the sword and the helm, ofcaurse). After many hundreds of years of fine tuning, however, the only use the sword had was to puncture the plate. That was very difficult, however, since the grade of steel was so hard... only blunt instruments and weighted axes had any use against plate armor in later medieval times. Makes me wonder why rapiers were so popular then and why less people wore plate (Other than it's obsene costs... a nice suit of armor would cost as much as a nice lexus does now... and a kings suit would be as much as a rols royce).