Ur was a mage of Dalaran before the coming of the Scourge. He was best known for his studies on shadow magic and his research on other worlds. He is most well known for his research on the alien creatures known as worgen. Though his knowledge was great, some believed that his conscience held him from true power. He died during the Siege of Dalaran at the hands of the Scourge.
The dark mage, Morganth also possessed a book written by Ur, , which the mages of Stormwind City wanted returned to them because they feared that Morganth might find a way to open it and read its contents.