'Outlander: Blood of My Blood' casts leaders of Clan Grant, MacKenzie

Peter Mullan will play Red Jacob MacKenzie on "Outlander: Blood of My Blood." File Photo by David Silpa/UPI

April 3 (UPI) -- Starz has announced new casting for the Outlander prequel, Outlander: Blood of My Blood.

The network said in a press release Wednesday that Brian McCardie, Jhon Lumsden, Sara Vickers and Peter Mullan have joined the cast of the upcoming series.

Outlander: Blood of My Blood will explore the lives and relationship of Jamie's parents, Ellen MacKenzie (Harriet Slater) and Brian Fraser (Jamie Roy) and Claire's parents, Julia Moriston (Hermione Corfield) and Henry Beauchamp (Jeremy Irvine).

The show will follow the two parallel love stories across two different time periods, with Jamie's parents in the early 18th century Scottish Highlands and Claire's parents in World War I England.

McCardie will play the leader of Clan Grant, with Lumsden as his son, Malcolm, a potential suitor for Ellen MacKenzie.

Vickers will portray Davina Porter, a housekeeper in the Lovat household and mother to Brian Fraser, while Mullan has been cast as Red Jacob MacKenzie, Laird of Clan MacKenzie and father to Ellen, Dougal, Colum, Janet and Jocasta.

Other previously announced cast members include Rory Alexander, Sam Retford, Séamus McLean Ross and Conor MacNeill.

Production is underway in Scotland.

Outlander: Blood of My Blood will feature Matthew B. Roberts as showrunner and executive producer.

The original Outlander stars Caitríona Balfe and Sam Heughan and will return for an eighth and final season on Starz this year.