Dorgar Adarbrent was an old Waterdavian noble of the Adarbrent family with a strong interest in preserving Waterdeep's traditions. He gave monetary support to old nobles who were down on their luck. Dorgar was often seen wandering the paths in the City of the Dead. 
In his youth he fell in love with a young noble girl. They were arranged to be married but she died of the fever when both she and Dorgar remained in Waterdeep to aid others during a plague.
In the Year of the Ageless One, 1479 DR, a rich merchant named Rampage Stunk bought several old tombs with the goal of tearing them down to construct his own massive tomb. Unfortunately, one of the tombs was Dorgar's fiancee's. In his anger, Dorgar used a necromantic spell from a spellbook belonging to a long-dead cousin to wake the dead and cause them to haunt Stunk's mansion. The spell was more powerful than Dorgar anticipated and things soon got out of hand.
A young wizard named Gustin Bone and his friend Sophraea Carver tracked the curse to Dorgar and he showed them how to reverse the spell and send the dead back to their tombs. As punishment for his actions, the ghost of one of Dorgar's long-dead ancestors decreed that Dorgar could not be buried in the family tomb. The punishment was irrelevant because Dorgar had long ago purchased a small plot next to his fiancee's tomb as his burial place.
Although kind at heart, Dorgar had a fiery temper.
Due to his age, Dorgar valued highly the old ways of Waterdeep, considering the city's traditions to be what older generations need to pass down to the younger ones. Dorgar, in turn, valued the city's nobility highly and felt deeply troubled by how many of those old families were struggling to survive.
Dorgar's regard for tradition further caused him to dislike much of Waterdeep's merchant class. He considered them to cause too much change in the city without regard for its history, and he resented them for feeling entitled to do so by simply being wealthy.
Dorgar was considered by much of Waterdeep's citizenry to look like a walking corpse.
- Canon material does not provide a year for the events described in Waterdeep: Dragon Heist, but Christopher Perkins answered a question via Twitter and stated the year was 1492 DR. Corroborating this, Dragon Heist page 20 refers to events of Death Masks (set in 1491 DR) as being "last year". Unless a canon source contradicts this assertion, this wiki will use 1492 DR for events related to this sourcebook and Waterdeep: Dungeon of the Mad Mage (which is referenced on pages 5 and 98 of Dragon Heist).