Orlak

Orlak was a powerful Vampire that ruled Westgate.

History
Before the Dale Reckoning Orlak was a powerful vampire and in -286 DR he proclaimed himself Night King and seized the city of Westgate; Orlak ruled for a century until the adventure paladin Gen Soleilon defeat the masted vampire and stop his reign. Considered dead Orlak became the ruler of the underdark of the city. Finally in 1370 Orlak vampirized one of the clone of Manshoon just at the start of the Manshoon's Wars. In this first act the Manshoon's vampire clone search and destroy his sire, putting a end of the undead life of Orlak.

Behind the Scenes
It's not really clear if was the same Orlak in -286 and 1370