Lee Unwin was a British soldier in the army who served in a unit in Iraq. Harry Hart chose Lee as his membership proposal for Kingsman position of Lancelot. Lee Unwin and James Spencer became the last two remaining candidates for the position of Lancelot. The two were sent on a mission to the Middle East in 1997 along with Harry Hart and Merlin. They had their target captured and tied down to a chair. Galahad shot the captive twice, but he survived and looked up at the Kingsman with a grenade pin in his mouth. Lee shoved Hart out of the way and jumped on the captive, using himself to contain most of the explosion that would've otherwise killed everybody in the room, but instead only killed himself.
Spencer then took the Lancelot position.
Lee's death had a profound impact on Harry, as Harry felt guilty of the weight his mistake and that Lee had died in order to circumvent the more dire consequences.
Lee's family hadn't fared well either, after his death because his widow, Michelle, entered an abusive relationship and later marriage with a drunkard and bully named Dean Baker, who Lee's son, Gary "Eggsy", deeply loathes. Gary had a promising future in the Royal Marines but took pity on Michelle, forgoing the prospect and turning to a life of delinquency as a result.
Hart later sought out Eggsy and had him enlisted for candidacy for the position of Lancelot, previously held by Spencer until he was killed by Gazelle.
- When Eggsy is in the interrogation room, the pin he is holding says 19. 12. 97. on it, which means that Lee died on 19 December 1997.