Sir Derek Jacobi ("I, Claudius", "Cadfael", "Gosford Park", "Gladiator") has signed on to play the lead villain in the upcoming "Underworld" sequel says Moviehole.

Jacobi, whose rumoured to be playing the character of Marcus in the follow-up, just completed a role in the British comedy "Nanny McPhee". The original film's co-stars Kate Beckinsale and Scott Speedman have just wrapped training in preparation for the Vancouver shoot under the helm of Director Len Wiseman.

This film is expected to include a long opening prequel segment set in medieval times where armour-clad vampire armies battle with packs of werewolves in an all out war. The rest will be modern day using cast from the first film.

Thanks to 'Clint'.