Game of Thrones may be over, but the end of the series certainly hasn't stopped fans speculating. While some have gone back to talking about what will change in the book series, and how things will be different for the Westeros on the page, others are still speculating about the future of Westeros on the screen - including who some of the new characters are from the final season. Unsurprisingly, HBO chose not to add too many new faces for the final episodes, but there were a few in the finale itself, at the council of lords and ladies gathered to decide Tyrion and Jon Snow's fates. Alongside the Starks and a few recognizable characters, the meeting included four unidentified Lords and a new Prince of Dorne, played by Toby Osmond.
Fan speculation over who this new Dornish prince could be has included theories of everyone from Quentyn Martell to a Lord of a completely different Dornish house, but there seemed to be no confirmation of exactly who he was. It was obvious that the character was the new Dornish Prince, thanks to his golden robes, but he wasn't named on screen, or officially named by HBO. However, Osmond has his own thoughts on who, exactly, he was playing.
In an interview with Screen Rant, Osmond revealed that although he wasn't given an official name, a few were suggested. He also revealed that he believes he is not Quentyn, but the younger brother of Doran and Oberyn. He said:
"Someone mentioned a possible name, but I think it was an invented name. So it would have just been a series name. A lot of people have suggested Quentyn Martell, of course. But just doing the math, I thought, well, Prince Doran’s kid… I’m just, I'm too old, unfortunately. There's no way I could be a brother of Trystane because he could probably be my son, to be honest. So I just figured I was the younger brother of Doran and the Red Viper. Or, there was an interesting fan theory about another house in SunSpeare and Dorne, I can’t remember the name of it. But I’d like to think that I’m a Martell."
He then added:
And Pedro Pascal [Oberyn], what a fantastic character as well, I was shocked. I was like "are you sure you’re casting ME as his younger brother", which is what I was assuming it was. Also, fun fact, I was given his scimitar, his sword that was custom made for his character. But he never used it. He used his spear of course. So yeah, on set, I had this beautiful snake-headed scimitar. It had, I think it was a cobra on the top of the hilt. And then the cross guard heads were snakes as well. Beautiful, beautiful sword.
While fans of the Quentyn theory will be disappointed to hear this, it does make some sense. In the books, Quentyn is the eldest child of Prince Doran, and would be in line to take his father's place as Prince. However, in the show, Quentyn does not appear - and Trystane is referred to as heir, which means that Quentyn isn't just off-screen, he doesn't exist. It could be argued that Quentyn could exist as a younger brother, but as Osmond points out, his age would make him more likely to be an uncle to Trystane than a brother - let alone a younger one. The appearance of the Martell sword also puts paid to theories that the new prince is from a different house, as the head of House Dayne would be carrying the famous Dawn (their house sword), not the snake-headed scimitar that was Oberyn's.
Of course, this is largely just the actor's opinion on who he could be, and is not confirmed by the showrunners or HBO. That said, given that his opinion is based on facts like his age and costume, it seems clear that he is truly a Martell... and not Quentyn. However, this would still mean that the character was created for the series, and not taken from the books, as A Song of Ice and Fire doesn't include another living brother to Doran and Oberyn. There were two other brothers in the family, Olyvar and Mors, but they are mentioned in A Feast For Crows as having died in infancy. Perhaps in Game of Thrones, Olyvar or Mors survived, and has now taken up his brother's sword and rule of Dorne.