'300' spinoff: 'London Boulevard's Jamie Blackley joins cast

Jamie Blackley has joined the cast of the 300 spinoff.

The London Boulevard actor will play Greek youth Calisto in the untitled movie, reports Deadline.

The 16-year-old follows his father into war only to find himself facing the terrifying Persian leader Xerxes.

Blackley has previously appeared in Casualty, Midsomer Murders and Misfits, and has a supporting role in Snow White and the Huntsman.

Formerly titled The Battle of Artemisia, the film is set at the same time as 300.

Zack Snyder's movie was based on the graphic novel by legendary Dark Knight Returns and Sin City creator Frank Miller.

Sullivan Stapleton (Animal Kingdom) was recently cast as Xerxes. Joel Edgerton was originally thought to have been in contention for the part.

Casino Royale star Eva Green is also reportedly in talks for a role in the film.

Noam Murro will direct the movie for Warner Bros and Legendary Pictures.