Angel is an American television series, a spin-off of the television series Buffy the Vampire Slayer. The series was created by Buffys creator, Joss Whedon, in collaboration with David Greenwalt, and first aired on October 5, 1999. Like Buffy, it was produced by Whedon's production company, Mutant Enemy.

The show details the ongoing trials of Angel, a vampire whose human soul was restored to him by gypsies as a punishment for the murder of one of their own. After more than a century of murder and the torture of innocents, Angel's restored soul torments him with guilt and remorse. During the first four seasons of the show, he works as a private detective in a fictionalized version of Los Angeles, California, where he and a variety of associates work to "help the helpless" and to restore the faith and save the souls of those who have lost their way.Cordelia: "Angel Investigations, we help the hopeless". Episode "Darla", Angel second season. Typically, this involves doing battle with evil demons or demonically allied humans, primarily related to Wolfram & Hart, a law firm. He also has to battle his own demonic nature.

The atmosphere of the show was darker, and at brief periods it managed to perform better than its parent series, though Buffy's overall yearly ratings always topped Angel's.Topping, Keith, Hollywood Vampire, (3rd edition, includes Season 4) Virgin Books (2004), page 360: "During 2002, Angel was getting slightly higher ratings than Buffy, aided by a new Sunday-slot and the popular series Charmed as its lead-in show." Also see Wahoske, Matthew J., "Nielsen Ratings For Buffy The Vampire Slayer, Angel, And Firefly", Insightbb.com (2004)