A familiar face from Downton Abbey shows up in House of the Dragon Season 3 Episode 2 to help Daemon (Matt Smith) and Rhaenyra (Emma D’Arcy) out of a pickle in King’s Landing this week. Ser Luthor Largent (Tom Cullen) is a new character on the HBO drama this season, but he’s a character readers of Fire & Blood know all too well…

**Spoilers for House of the Dragon Season 3 Episode 2, now streaming on HBO Max**

When Daemon and Rhaenyra arrive in King’s Landing in this week’s House of the Dragon, they immediately discover that Alicent (Olivia Cooke) managed to get the gates open, Aemond (Ewan Mitchell) out of town with Vhagar, and most of the Red Keep’s soldiers to stand down. However, a core contingent of guards loyal to House Hightower persist in standing in their way. Daemon takes care of most of these soldiers in style, but for a brief moment, it seems that the City Watch, aka the gold cloaks, will support the Hightower loyalists.

However, Ser Luthor Largent immediately switches sides to declare his support for Rhaenyra. (It’s a classic gold cloak betrayal!)

While at first glance, it might seem that Alicent was successful in convincing Ser Luthor to aid her, the truth is that he’s actually a long-time friend and ally of Prince Daemon. If you remember — all the way back in the very first episode of House of the Dragon — Daemon was once the head of the City Watch. He was instrumental in transforming them into a force to be reckoned with in King’s Landing. A key part of this? He gave them the fancy gold cloaks. It’s a simple article of clothing that gave the men pride and led to their nickname.

Daemon immediately recognizes Ser Luthor and the two greet each other as friends. But who exactly is Ser Luthor Largent in the George R.R. Martin books? Who plays Ser Luthor? And should Rhaenyra and Daemon really trust him?

Who is Ser Luthor Largent in House of the Dragon Season 3? All About the Tom Cullen Character:

Ser Luthor Largent was Commander of the City Watch during the time of the great Targaryen civil war known as the Dance of the Dragons in George R.R. Martin’s books. So far, on House of the Dragon, he seems like a pretty charming man, but he cuts a more unnerving figure in Fire & Blood. In Fire & Blood, we’re told Ser Luthor allegedly killed a warhorse with a single punch. He was supposedly close to seven feet tall, and would later be accused of several ghastly war crimes still yet to come on the HBO show.

Part of the reason why HBO’s version of this character already seems more likable is he’s being played by Tom Cullen. You might remember the 40-year-old Welsh actor from History’s Knights Templar drama Knightfall or Starz’s Becoming Elizabeth. However, Cullen is probably most famous for being one of Lady Mary’s (Michelle Dockery) dashing suitors in Downton Abbey. Anthony Foyle, Viscount Gillingham vied for the heroine’s affection after the death of Cousin Matthew (Dan Stevens).

If House of the Dragon follows the events of Fire & Blood, Ser Luthor Largent will be one of Daemon and Rhaenyra’s most trusted lieutenants, willing to do awful things for Team Black. He also will eventually be defeated by an irate mob of smallfolk who rebel against Rhaenyra. (At least, that’s what happens in the book version of the story.)

House of the Dragon has already changed a key detail about Ser Luthor’s story. In Fire & Blood, Ser Gwayne Hightower (Freddie Fox) is placed in the City Watch as his second-in-command. Ser Luthor ruthlessly kills Ser Gwayne during the sacking of King’s Landing. When we asked Freddie Fox how relieved he was to be on the road with Ser Criston Cole (Fabien Frankel) in Season 3, he joked he was “surprised and thrilled.”

“I didn’t think I was going to make it through Season 2,” Fox said.

New episodes of House of the Dragon come out Sundays at 9 PM ET on HBO and HBO Max.