Duncan discovers Egg's true identity as Aegon Targaryen in a pivotal moment during the events of George R.R. Martin's A Knight of the Seven Kingdoms: The Hedge Knight.

This revelation unfolds at the Ashford Tourney, where tensions erupt after Ser Duncan the Tall (Dunk) defends a puppeteer named Tanselle from Prince Aerion Targaryen's cruelty. Dunk strikes Aerion in retaliation, leading to his capture and a brutal punishment ordered by the prince—having all of Dunk's teeth knocked out.

The Dramatic Reveal

Egg bursts into the scene, commanding Aerion's guards by name to halt, declaring they'll answer to his father, Prince Maekar.

Aerion sneers at Egg's bald head and lowborn guise, but Egg retorts sharply: "I cut it off, brother. I didn't want to look like you."

This exchange exposes Egg as Prince Aegon Targaryen, the youngest son of Maekar and grandson of King Daeron II—far from the humble squire Dunk believed him to be.

Book vs. Show Context

  • In the novella (The Hedge Knight): The reveal happens publicly right after Dunk's clash with Aerion, mirroring the dramatic standoff. Dunk learns it here, though subtle hints built up earlier, like Egg's unexplained knowledge of courtly matters.
  • In the HBO series (A Knight of the Seven Kingdoms): It aligns closely, dropping in Season 1, Episode 3 (aired around February 2, 2026), after a similar puppeteer incident and retaliation. Fans buzzed online, calling it the "first big twist" with Easter eggs foreshadowing it in prior episodes.

Why It Matters in Westeros Lore

Egg shaves his distinctive Targaryen silver hair to travel incognito, seeking real adventures away from palace life—hence meeting Dunk at an inn.

Their bond endures; Egg (Aegon V, "the Unlikely") later becomes king, with Dunk rising to Kingsguard Lord Commander. Tragedy strikes at Summerhall, where both perish in a fire during a dragon-hatching ritual.

TL;DR: Dunk finds out at the Ashford Meadow trial post-Aerion fight, when Egg intervenes as royalty—Episode 3 in the show, end of The Hedge Knight in books.

Information gathered from public forums or data available on the internet and portrayed here.