Not only is Jefferson Hall the first actor in Game of Thrones to simultaneously play two characters on-screen, but he’s also the first actor to have appeared in both shows. Before portraying House of the Dragon’s Lannisters, Jefferson Hall played Ser Hugh of the Vale in Game of Thrones season 1. His role also wasn’t a quick and forgettable appearance, as Ser Hugh has a particularly memorable death by The Mountain. In Game of Thrones’ season 1 episode 4, Hugh went up against Ser Gregor Clegane in a joust, which ended in a splintered lance being lodged in his neck. Hugh was also notable for his suspected role in Jon Arryn’s death before being killed by The Mountain, with Eddard Stark noticing the newly knighted character’s arrogance. Since Jefferson Hall only appeared in one episode of Game of Thrones as Ser Hugh, House of the Dragon’s Lannisters are a step up for the actor’s presence in the franchise.
Perhaps the most notable actor to be reused in Game of Thrones’ original series was Dean-Charles Chapman, who took over the role of Tommen Baratheon in season 4. The character had previously been played by Callum Wharry, but Chapman stepped in when Tommen was abruptly aged-up and made more significant as the king. Prior to playing Tommen, Chapman appeared as another member of House Lannister for two episodes of Game of Thrones season 3. While he was only briefly shown on-screen, Chapman portrayed 15-year-old Martyn Lannister, who was killed in his cell by Rickard Karstark when held by Robb Stark’s army in their campaign for the Iron Throne.
While Jefferson Hall playing three different characters with notable roles in the story is impressive, his recent Lannister roles still don’t bring him the record for portraying the most figures on Game of Thrones. This accomplishment goes to Ian Whyte, who played a total of five characters in Game of Thrones – a record that could continue to grow if he returns for House of the Dragon. Whyte first joined Game of Thrones as the pilot’s White Walker, a role he reprised in season 2, then became the second actor to play The Mountain. His last three roles in Game of Thrones were all giants from beyond the Wall, including Wun Wun, Dongo the Doomed, and an unnamed wight giant who killed Lyanna Mormont in the Battle of Winterfell.