“The Walking Dead” actress Sonequa Martin-Green has landed the lead role on CBS All Access’ “Star Trek: Discovery.”

Sources confirmed to Variety that the actress will continue as a series regular on the AMC zombie drama while tackling the lead role on CBS’ relaunch of the science-fiction television franchise.

A representative for CBS declined to comment.

The casting of Martin-Green brings to a close a lengthy search for a lead on “Discovery,” which has struggled with delays since being given a greenlight by CBS last year. Original showrunner Bryan Fuller had at Comic-Con this summer indicated that he wanted to cast a woman of color in the lead role, citing inspiration from Mae Jamison, the first African-American female astronaut and Nichelle Nichols, the lone African-American and lone female cast member on the original “Star Trek” series. In August, speaking at the Television Critics Association press tour, Fuller confirmed that the lead character would be a woman and that she would not hold the rank of captain, as “Star Trek” leads traditionally have.

Fuller exited the showrunner role in October, after CBS was forced to push back the series premiere from February to May, and was replaced by fellow executive producers Gretchen Berg and Aaron Harberts. The casting search continued to drag on, with CBS Television Studios, which is producing the series, focusing its efforts on casting an African-American or Latino actress.

Martin-Green’s character will hold the rank of lieutenant-commander, though the character’s name is still unknown. The actress has played Sasha Williams on “The Walking Dead” since the show’s third season. Her other credits include CBS’ “The Good Wife” and ABC’s “Once Upon a Time.”

Martin Green becomes the seventh actor cast on “Discovery,” following Doug Jones, Anthony Rapp, Michelle Yeoh, Chris Obi, Shazad Latif, and Mary Chieffo.

“Discovery” will be the first “Star Trek” series since “Enterprise” ended its run on UPN in 2005. It will premiere in May on the CBS broadcast network, with subsequent episodes streaming exclusively in the U.S. on CBS All Access. The show is set to take place 10 years before the events of the original “Star Trek” television series.