First a bit of history.
The lands of Tamerel have survived though three eras. The first was high magic and grand adventure. During this era a small group of adventurers appeared. They showed themselves in such glorious ways that their legends only grew. There was a young thief, Sparrow, a half-elf girl with a wicked blade and a wild sense of humor, The Red Witch, a cleric of the goddess of seduction, her name came from her outfit, Malik, a necromancer with his eyes set on the Red Witch, and a fighter that protected them, Goran. The group made it their mission to defend the people and destroy the great evils of their day. The first era ended when three of them were killed by a cataclysm of magic. Malik survived. His love lost he set about trying to find the cause of the cataclysm. The Red Witch's fellow clerics sent many young women to aid his search. The last one they sent was a man that was seeking the raiment of the original Red Witch. Malik crushed the order without though. His research took a great deal of his energies and was going to kill him. Knowing that undeath was better for research than life, he set up the items he would need to become a Lich. He did not have to wait long as his own experiments killed him shortly thereafter. A thousand years later, Malik the Lich figured out the first cataclysm. He learned it was a clash of the gods. His sorrow turned into rage and then into despair. He destroyed his lab and turned his eyes back to the world. It had grown decrepit and rotten to his eyes. A group of heroes hunted down the lich and put him to rest, never finding his soul.
His death was the turning point of the second era. The times became harder and harder to stem the flow of evil beasts invading the good lands. The priests found ancient text speaking of a cleansing of the dark beasts in the oldest library. Five thousand years after the death of Malik, the gods were begged to cleanse the lands again, and they did. The ground shook and everything was laid to ruins. The oldest tombs were unearthed and the lich Malik was released. He looked out at the destroyed lands and saw only the destruction that killed his beloved. He sat back and watched. The human kingdoms grew in power, as did the Elven lands and the Dwarvish strong holds. He was please to see them defending themselves. He disguised himself and went among the people. He saw the world was no different from the days he searched for an answer. He asked of the Red Witch's people. No one knew the name. He searched for any sign of them, and found none. His rage returned how the humans dared to forget such a heavenly gift. He turned his rage into a plan. He went to the evil races, and showed them his true power. Many fell into step with him and without thought brought their allies into his army. The world of Tamerel would fall under his mighty grip in one summer. He went forth with his armies. Destroying towns and using his knowledge of Necromancy to raise a larger army. The more that died the stronger he became. He destroyed the kingdoms as he came upon them without mercy or pity. His armies were unstoppable. The Elven arrows were not powerful enough to slow his forces; the dwarven hammers could not forge armor strong enough to defend themselves from his hordes. The humans and their strengths could not protect their lands. Malik pushed them back and then swept along to destroy everything in his path. The final area was a single plateau in the middle of what was once a no man's land, at the point where the gods brought all their magics to bear to destroy the lands. The area was protected from all evil beasts, undead and alive alike. The live evils could walk the land but it took a great toll on them and they soon lost their ability to fight. The undead were destroyed outright.
Malik felt the lands before they destroyed him. They were too powerful for him to defeat. He pulled back and set up a keep to watch over the light lands. His keep was well defended from magic in all forms. He forgot one simple thing. Not all people fight with magic. A young rogue and a dwarven knight were able to sneak in to his lair and crush the soul jar, at the cost of their lives. The girl had been called Sparrow, and her dwarven knight, Goran. Malik was so stunned to see them he did not try to stop them. Their deaths gave an assassin is only chance to end the reign of Malik. The assassin drove a blade deep into the heart of the lich and brought the house down on the corpses. Nothing ever came out of the rubble. The legend goes that the three that went in knew it was a one way trip, but went anyway. This destruction was the end of the Third Era.
500 years have passed. Few remember what caused the collapse of the great castle outside the holy lands. Those born with darkness in their hearts find their way out of the lands. The lands have been divided into two great kingdoms within the holy lands.
The Human Kingdom of Tamerelson - Many of the races of Tamerel frequent the cities, there are human and Halfling in great numbers. It is not surprising to see any of the good races there. Elves, Eldarin, and Dwarves are not so frequent.
The Elven Kingdom of Last Home was built in an ancient forest long forgotten by the elves and Eldarin. They made their homes here and shunned all contact with the outside world. Recently there have been a few more Elven trade caravans going into the human lands for items that they want.
The dwarves went into the plateau itself. They made no effort to aid either the humans of the elves in their attempts to build up a home. The dwarves carved out a great city in the stone and made themselves a new city. Only the Dragonborn have seen the inside of this city, they helped build it. The dwarves shun all but the dragonborn and do not seek to re-establish contact as yet. The Dragonborn do that for them. They trade with the humans and other races.
Teiflings find the holy lands uncomfortable due to their infernal blood. Some teiflings have found ways to ignore the effects of the holy land.