The 39-year-old actor and 18-year-old actress would play Alaric Saltzman and Hope Mikaelson in the new CW series, according to Variety.
Davis and Russell would join Quincy Fouse, Jenny Boyd, Kaylee Bryant and Aria Shahghasemi. TV Line previously reported Shahghasemi's character will debut in the fifth and final season of The Originals.
Deadline said The Originals spinoff will center on Hope and the younger generation of Originals. Sources said the show will be introduced in a short video presentation instead of a regular pilot.
The Originals is a spinoff of The Vampire Diaries, which ended in March 2017 after a seven-season run. The Originals stars Joseph Morgan and Daniel Gillies, and will debut its fifth and final season in April.
Davis played Alaric in The Vampire Diaries and Season 4 of The Originals, and will return as a guest star in Season 5. Russell will debut as Hope, the daughter of Niklaus Mikaelson (Morgan) and Hayley Marshall-Kenner (Phoebe Tonkin) in Season 5.
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