It has a gala performance in Stratford-upon-Avon on Saturday evening in a reconfigured Royal Shakespeare theatre with a capacity of 870. View image in fullscreen Noah Ritter as Prince Rhaegar Targaryen and Harmony Rose-Bremner as Lyanna Stark in The Mad King. The Mad King – which unfolds on a cross-shaped stage with the audience all around and has a cast of three dozen – weathered a challenging period of previews. View image in fullscreen Michael Shaeffer as King Aerys II Targaryen in The Mad King. The Mad King is widely tipped to follow hot on its heels.