Game of Thrones season 8 episode 2 "A Knight of the Seven Kingdoms" aired earlier this week and finally showed Jon Snow revealing the biggest secret of his life to his lover (or aunt) Daenerys Targaryen. As of now, Jon does not have solid proof about his parentage and there is only one person in the entire Westeros who can prove his true lineage.
Back in Game of Thrones season 8 episode 1 "Winterfell," Samwell Tarly revealed to Jon Snow that he is the son of Rhaegar Targaryen and Lyanna Stark. Most of the Westeros, including Jon and Daenerys, thought that Rhaegar Targaryen kidnapped Lyanna Stark but Bran Stark revealed that Rhaegar and Lyanna were actually in love and had a secret wedding ceremony. From their short marriage, they had a child who was raised by Ned Stark as his own bastard son.
As per Samwell Tarly, Ned Stark lied to everyone in order to save Jon because he knew that if Robert Baratheon will learn about this then he will kill the baby boy.
We all learned about this by Bran Stark and Samwell Tarly. Even Jon Snow trusts his best friend but what about Daenerys Targaryen? How is she going to get convinced that Jon is Aegon Targaryen?
When Jon Snow tells Daenerys Targaryen that Lyanna Stark and Rhaegar Targaryen were his parents, the would be Mad Queen had this to say:
"A secret no one in the world knew except your brother and your best friend. Doesn't it seem strange to you?"
If you have read George RR Martin's books or have watched previous seasons carefully then you must know that there is the only person in the entire Westeros who can confirm the details about Jon Snow's parentage — Howland Reed.
Howland Reed was there when Ned Stark found his sister giving birth to Jon Snow in that far away castle, Greywater Watch. Many fans have assumed that Howland Reed was the 'old friend' Bran Stark was waiting for instead of Jaime Lannister.
In the upcoming Game of Thrones season 8 episode 3 rumored title "Battle At Winterfell", we may see the end of Daenerys Targaryen or Jon Snow and if that happens then the story will go on without Howland Reed but if these two survive and if Daenerys still needs a proof then they will have to bring Howland Reed to the Westeros to confirm that Lyanna Stark did give birth to Rhaegar Targaryen's child in that castle.
Game of Thrones season 8 episode 3 rumored title "Battle at Winterfell" will air next Sunday on HBO.
