Game of Thrones and Star Trek veteran Alexander Siddig has been cast as the formidable Ra’s al Ghul in Fox’s Gotham, the prequel series to Batman’s origin story. The young Bruce Wayne (David Mazouz) has been gaining greater agency on the show, which focuses primarily on Ben McKenzie’s portrayal of a younger Commissioner Gordon.

The Court of Owls has factored prominently this season as the shadowy organization looking to take over the Wayne empire. As it turns out, the mastermind behind it all will be none other than Siddig’s Ra’s al Ghul, who also leads the League of Shadows.

Fans will likely remember Alexander Siddig as Prince Doran Martell on Game of Thrones, the now deceased ruler of Dorne and elder brother to the fan favorite Oberyn Martell (also dead). Sci-fi buffs will know him best from his role as Dr. Julian Bashir in Star Trek: Deep Space Nine, one of the show’s main characters.

Matt Nable's Ra's al Ghul as he appears on The CW's 'Arrow.'

The character of Ra’s al Ghul is consistently one of Batman’s most terrifying adversaries. Liam Neeson’s depiction of the character trained Christian Bale’s Bruce Wayne in Christopher Nolan’s films, and more recently, Matt Nable’s was a primary antagonist throughout Arrow’s Season 3 on The CW. He’s typically centuries old, made almost-immortal through the use of the magical Lazarus Pit (DC’s sinister stand-in for the fountain of youth).

Gotham returns on April 24, but don’t expect Siddig’s assassin leader to appear that soon.

Photos via DC Universe