Vaelish was scheming and arrogant. He had great confidence in his own intelligence and little respect for the intelligence of others, which he enjoyed letting them know. He specialized in the school of abjuration.
When Vaelish first arrived in Icewind Dale, he conspired to undermine and conquer the area. With his plot, Vaelish hoped to elevate his master Jendrick to the position of Archmage Arcane so he could replace him as Master of the North Tower. While incarcerated for these efforts, his only goal was to obtain his freedom.
Vaelish was born in Athkatla in Amn. At a young age, he discovered his magical powers and joined the reformed Arcane Brotherhood in Luskan. Here, Vaelish soon rose through the ranks until he became an apprentice of Jendrick the Blue, Overwizard of the North Tower.
In the Year of the Awakened Sleepers, 1484 DR, Vaelish and his apprentice Pallidor, along with some thugs of Ship Rethnor, settled in Bryn Shander and started a plot to conquer Icewind Dale. To all in the Ten Towns, he appeared as just a merchant who served as an aide to the Speaker of Bryn Shander, Duvessa Shane. However, he worked behind the scenes to establish a protection racket and to undermine the economy of Ten Towns. At the news of several threats to the dale (some secretly instigated by himself), he proposed a no-confidence vote to replace Duvessa in the Year of the Iron Dwarf's Vengeance, 1485 DR.
When his schemes were discovered and foiled, Vaelish was sent to the prison of Revel's End with a lifetime sentence. While he initially hoped to be rescued by the Arcane Brotherhood, he quickly came to realize that his fellow wizards had abandoned him as his failures were seen as an embarrassment. While incarcerated, he was known as "Prisoner 237."
During the Everlasting Rime, many folk of Icewind Dale suspected that the endless winter was caused by the Arcane Brotherhood. In the Year of the Warrior Princess, 1489 DR, Duvessa Shane sought to question Vaelish about these rumors, and was willing to reduce his sentence in exchange for his cooperation.
- R.A. Salvatore, James Wyatt, Jeffrey Ludwig (November 19, 2013). “Adventure”. Legacy of the Crystal Shard (Wizards of the Coast), p. 20. ISBN 0-7869-6464-2.
- Kim Mohan ed. (2015). Sword Coast Adventurer's Guide. (Wizards of the Coast), p. 98. ISBN 978-0786965809.
- Christopher Perkins (September 2020). Icewind Dale: Rime of the Frostmaiden. Edited by Kim Mohan. (Wizards of the Coast), p. 160. ISBN 978-0786966981.
- Christopher Perkins (September 2020). Icewind Dale: Rime of the Frostmaiden. Edited by Kim Mohan. (Wizards of the Coast), p. 12. ISBN 978-0786966981.
- R.A. Salvatore, James Wyatt, and Jeffrey Ludwig (November 19, 2013). Legacy of the Crystal Shard. (Wizards of the Coast). ISBN 0-7869-6464-2.
- Christopher Perkins (September 2020). Icewind Dale: Rime of the Frostmaiden. Edited by Kim Mohan. (Wizards of the Coast), p. 104. ISBN 978-0786966981.