Dialiah is the goddess of love and nature in the TDDC universe. She also has some power over healing.
She was the lover of King Kelvoras of the Eladrin, who forged the Colana Dialiah as a gift for her. She refused to accept it as a) she would be likely to lose it while running around in animal form and b) it could be interpreted as a mark of ownership over her.
When Kelvoras died in the Shatterwar, Dialiah took it somewhat poorly and cursed the Orcs, stating that "for a thousand years, nothing will survive your footsteps". This curse created a drought in Urruk, turning it into a desert.