Bok was a Ferengi DaiMon in the early 2360s. His only son was killed in the Battle of Maxia when his ship was destroyed by the USS Stargazer, under the command of Captain Jean-Luc Picard. This affected Bok greatly, and he plotted his revenge for years. He attempted to carry it out in 2364 when he used a thought maker to influence Picard's actions. He tried to trick Picard into attacking the USS Enterprise-D, but his plot was foiled. He was subsequently relieved of command of his ship by his first officer Kazago for his "unprofitable venture". (TNG: "The Battle")
Bok was stripped of his title of DaiMon soon after and was incarcerated at Rog Prison, though he eventually bought his way out and made his way to the Dorias Cluster. Bok again tried to obtain revenge on Picard in 2370, by killing his son, Jason Vigo. Picard had been unaware of the existence of Vigo until Bok's threat against him. It was later discovered that Vigo was not his son, but his DNA had been altered by Bok to make it appear that way. Bok failed to kill Vigo, prevented by Picard's intervention. His Ferengi associates, having been told it was a plot to make Picard pay ransom money, turned against him after learning the truth. (TNG: "Bloodlines")
In the Star Trek: The Next Generation Companion, author Larry Nemecek said that actor Frank Corsentino couldn't be located to reprise Bok in "Bloodlines," so Lee Arenberg stepped into the role (despite having played another Ferengi, Prak, earlier that season on "Force of Nature"). Evidently, Corsentino was later "found" and played Gegis in the Star Trek: Voyager episode "Inside Man".
Bok's face, belonging to Frank Corsentino's, was reused for the character of Aramut in the 1995 video game Star Trek: The Next Generation - A Final Unity. Corsentino was not credited in the game, however.