Event: Samwell Tarly - Secret Discovery (Political Wins)

Episode 7: The Dragon and the Wolf at 69:17
Sam puts the pieces of Bran's visions about Jon Snow's parentage together, remembering what Gilly told him at the Citadel about Rhaegar Targaryen's secret wedding.

"At the Citadel, I transcribed a High Septon's diary. He annulled Rhaegar's marriage to Elia. He wed Rhaegar and Lyanna in a secret ceremony."
(Secret Discovery)