Warning: This article contains major spoilers for the House of the Dragon season one premiere and the Game of Thrones series.
New series House of the Dragon has just premiered and its first episode features a surprising prophecy that may change everything you thought you knew about the Iron Throne in the original series, Game of Thrones.
Specifically, the prophecy concerns the 'Prince that was Promised' - a hugely important factor in George R R Martin's Song of Ice and Fire series of novels that has spawned many fervent fan theories over the years.
House of the Dragon S01E01 centred around Paddy Considine's King Viserys Targaryen I choosing his heir to the throne, which was complicated by his having no living sons borne to him.
Faced with the choice of either his brother Daemon or his daughter Rhaenyra, Viserys chooses Rhaenyra as his heir - but not until he's told her more of the first Targaryen king in Westeros and the man that united the seven warring kingdoms of the continent into one that he could rule.
The original prophecy of the Prince that was Promised foresaw the hero Azor Ahai would be reborn and bring about the end of the Long Night, as foreseen by Aegon Targaryen, the founder of the Targaryen dynasty.
For years during Game of Thrones' original broadcast, fans had argued the prophecy referred to Jon Snow, who was reborn after his death.
Others claimed it referred to Daenerys Targaryen, who was also reborn in Game of Thrones when she walked into flames with three stones and rose from the ashes with three dragons at the end of the show's first season.
Viewers of the show know that Aegon's vision did come true with the Night King invading Westeros in the final season - and that it was Arya Stark who ended up killing the Night King and stopping the threat.
However, in the closing moments of the House of the Dragon's premiere episode, Viserys reveals how the prophecy ties the Targaryen dynasty more closely with the White Walkers.
"Ambition alone is not what drove [Aegon] to conquest - it was a dream," Viserys says.
"Aegon foresaw the end of the world of men. It is to begin with a terrible winter gusting out of the distant north. Aegon saw absolute darkness riding on those winds, and whatever dwells within will destroy the world of the living."
Viserys then shares the secret that, according to Aegon's prophecy, the world of men can only survive if a Targaryen is seated on the Iron Throne.
"I have wasted the years since you were born hoping for a son," he tells Rhaenyra.
"This secret, it's been passed from king to heir since Aegon's time. And now you must promise to keep it and to carry it.
"Aegon called his dream 'A Song of Ice and Fire'."
The confirmation in the show's first episode demonstrates how directly Targaryen lore helps save Westeros in the final episodes of Game of Thrones when the White Walkers attack humankind.
But how that will play out now that Viserys' brother Daemon has been scorned remains to be seen in the remaining nine episodes of season one.
House of the Dragon is an HBO show that is streaming now in New Zealand via Neon.
