This Article Contains Spoilers - WARNING: This article contains major spoilers. If you do not wish to know vital information on plot / character elements in a story, you may not wish to read beyond this warning: We hold no responsibility for any negative effects these facts may have on your enjoyment of said media should you continue. That is all.
Anguy the Archer is a commoner from the Dornish Marches. At the Tourney for Eddard Stark becoming Hand Anguy wins the archery competition, outshooting Ser Balon Swann and Jalabhar Xho at a hundred paces and gaining the reward of ten thousand golden dragons. He squanders it on whores, food and wine.
When Ser Gregor Clegane "the Mountain that Rides" begins raiding the Riverlands Lord Eddard Stark sends a hundred men under the Marcher Lord Beric Dondarrion to arrest the Mountain. As However they are ambushed at the Mummer's Ford and Beric is wounded by the Mountain's lance. Edric Dayne pulls from the water and stands over him while the fighting happens, though Beric dies. The Red Priest Thoros of Myr, who was in the party and is a friend of Beric, performs the last kiss on Beric, a rite of R'hllorism. To his astonishment Beric is brought back to life. Beric rallies the survivors to fight the Lannisters' invasion of the Riverlands. However when King Robert dies the Lannisters usurp the throne, making Beric and his men outlaws. Eddard Stark is executed by the Lannisters' King Joffrey Baratheon. Eddard's son Robb Stark arrives in the Riverlands to fight the Lannisters, and on hearing of his father's death the Northmen and Rivermen at Riverrun proclaim him King in the North.
The war between the Lannisters and Starks leaves the Riverlands in ruins. Beric raids the Lannisters' foraging parties. Though some of his men die, others join Beric's force, who become the Brotherhood without Banners. His lightning-style raids and the Dondarrion sigil, a forked purple lightning bolt on black field speckled with four-pointed stars, lead to Beric becoming known as the Lightning Lord. Though Beric and his men were originally sent to fight the Lannisters, the Brotherhood fights all who oppress the smallfolk. Beric is killed five times but each time Thoros revives him.
Like most members of the Brotherhood, Anguy has become a follower of R'hllor. As they need money to buy food for the smallfolk, the Brotherhood decide to ransom Arya to Robb Stark.
At a Sept, the Brotherhood, including Beric and Anguy, with Arya, encounter a band of Brave Companions, a vile sellsword company who originally fought for Tywin but have turned their cloaks to the Starks. This band is being led by Septon Utt, a pedophile rapist and murderer. The Brotherhood hang him for his crimes.
In what becomes known as the Red Wedding, Robb Stark, his mother Catelyn Stark, and most of their army are massacred and Catelyn's brother Edmure Tully captured by their treacherous vassals, the Freys and Boltons, who have secretly joined the Lannisters. Catelyn is stripped and thrown in the river after a day and a night. Arya, while warging into her direwolf Nymeria, finds her mother and drags her out of the water. She is found by the Brotherhood and Harwin, a former guardsman of Winterfell, begs Thoros to bring her back. However Thoros claims she has been dead too long. Beric then performs the last kiss on her, and Catelyn rises, while Beric dies a seventh and final time. Leadership of the Brotherhood is taken by Catelyn, who becomes known as Lady Stoneheart. Stoneheart's mission, to take vengeance on all those she believes connected to the Lannisters, leads the outlaw band to fracture. Some, including Anguy, go their separate way.