Gwaine was born to a knight and his wife. His father died fighting for Caerleon, and when his mother went to plead help from the king he refused to help, leaving Gwaine's family impoverished. All Gwaine has left of his family heritage was a gold ring and a dragon scale necklace with his family crest hidden on it. Gwaine's opinion of the nobility was forever altered: he thought all nobles were blinded by power and greed. He eventually left home and began living a vagabond lifestyle, travelling the world using only his sword.
Meeting Merlin and Arthur
He first met Arthur and Merlin after he used his fighting skills to aid them in a tavern brawl. He was badly wounded while protecting Arthur from Dagr and brought back to Camelot to be treated by Gaius. Upon his recovery Gwaine is surprisingly dismayed to learn he saved a prince and is prepared to leave as soon as possible even refusing a congratulatory ceremony in his honor from King Uther Pendragon. Gwaine explains due to his previous experiences with the nobility he chose to avoid them. Gwaine later revealed to Merlin that while he does not specifically hate all nobility, he had yet to find one with inner nobility who is "worth dying for."
Gwaine decided to stay however when he caught sight of Camelot's splendor from a window of the castle. Unfortunately, Gwaine's relaxed and vagabond lifestyle proceeded to get him in to trouble with the locals and Arthur. Nonetheless, Merlin found Gwaine's enjoyment of life amusing and refreshing, telling him later "You livened things up!" The two developed a bond over their lack of a paternal figure. According to Gwaine, his father's life taught him one important lesson, that titles do not define nobility but rather whom the person is inside and their actions.
Merlin discovered that two of the knights, Sir Oswald and Sir Ethan, competing in the Melee Camelot was hosting are planning to kill Arthur when he found their swords are Stratle blades, swords that look blunt to the naked eye but were dangerously sharp in reality. On further investigation, Merlin discovered that Oswald and Ethan are in fact Dagr and Ebor, the two thugs whom Gwaine had saved Arthur from, in disguise. When Dagr and Ebor catch Merlin in their chambers, Gwaine intervened to protect him from them. He quickly dispatched both of them again with his sword fighting skills but was caught by Sir Leon and brought before the king for attacking two knights.
Uther sided with the supposed knights who claim Gwaine attacked them without cause; provoking a passionate response from Gwaine about the deeper meaning of nobility. Uther was prepared to execute Gwaine for breaking the knight's code of a peasant attacking a knight but Arthur vouches for Gwaine since he saved his life. Uther decided to banish him instead and warned he would be killed should he be caught back in Camelot. Gwaine was unbothered by this despite Merlin telling him he should reveal his true identity to the court. Gwaine refused, saying he never stays in one place too long anyway but told Merlin to help Arthur.
Gwaine took a liking to Gwen when he first saw her in the market and attempted to charm her by giving her a daisy. However, she politely refused Gwaine's attentions. The pair later saw each other again after Uther exiled Gwaine from Camelot; he quickly realised that Gwen was in love with Arthur. Her words, together with Arthur's protests and Merlin's vouches, reinforce Gwaine's belief that Arthur was indeed a noble man. He then supposedly leaves.
However, Arthur's kindness compelled Gwaine to return and he secretly enters the Melee and duels alongside Arthur against his assassins. Merlin and Arthur guess his identity by his fighting style and Arthur allowed him the victory in the tournament as thanks for aid in battle. He was soon arrested again by Uther who demands he be executed immediately. Gaius however showed Uther that Gwaine has once again saved Arthur by removing the blood crystals from the corpses of Sir Oswald and Sir Ethan to show their deception.
Unfortunately, Uther did not lift his banishment forcing the future knight to leave once again despite Arthur telling him if it were up to him, he would be welcome as a friend. Before leaving again, Merlin asked Gwaine to reveal himself, as it would mean he would be absolved and allowed to stay. Gwaine again refused saying he could not serve under someone like Uther but agreed with Merlin's observation that he fought well with Arthur and said perhaps someday he may return to Camelot when Arthur is king hinting at his future destiny.
Gwaine was later reunited with Merlin in another tavern brawl and helped him save Arthur from being killed by Morgana's Eye of the Phoenix as well as a pair of Wyvern. Gwaine was referred to as Strength by the guardian of the bridge into the Fisher King's kingdom while Arthur was named Courage and Merlin was named Magic. With Gwaine and Merlin's help Arthur retrieved what he had set out in search for; the Golden Tridant. They headed back to Camelot together, but since Gwaine was still banned from entering the kingdom he bid farewell to Arthur and Merlin.
Knight of the Round Table
The threesome are later reunited a second time, when after being captured Jarl, they meet him in Jarl's dungeon, he sums up his capture as "Wrong place, Wrong time, Wrong drink". To save Merlin, Arthur puts himself forward to face Jarl's champion, only for it to be revealed to be Gwaine. The two fake a fight, however soon find themself in trouble, when they have to kill each other, Merlin manages to save them by starting a fire, afterwards Gwaine joins them on their quest for the the Cup of Life. After they get it from the Druids, and are ambushed by Cenred's men, Gwaine stays with Merlin while Arthur is injured. After he gets slightly better (Thanks to Merlin's spell), he continues with them into Camelot, to find it captured, after finding Elyan and Gaius, Arthur sends him and Elyan to take Gaius to the woods, while he and Merlin try to save Uther.
He, along with the others, lived in the cave for a week until they were joined by Sir Leon and Guinevere. However they were ambushed by Morgana's soldiers and were saved by Lancelot and Percival. Gwaine went with them to the Castle of the ancient kings of Camelot, promising his allegiance to Arthur in the fight to retake the kingdom- noting that, while he believed they had no chance, he wouldn't miss this fight for the world- and was knighted by Arthur. Afterwards he joined them in their attack on Camelot to save Uther and the other knights. He distracted some of Cenred's Men so that the others could comtinue on their way to the cup of life and the dungeons. He comes back after Elyan asks if he is still alive. He replies: "What do you think? And it's Sir Gwaine to you" Gwaine is later shown riding into Camelot with the other Knights of the Round Table, now wearing the armour and robes of a true knight of Camelot.
A year later, Gwaine is still a Knight of the Round Table and is serving Arthur in Camelot. Merlin catches him, along with Percival, attempting to steal a large chicken leg from the castle kitchens. Later, he accompanies Arthur as they journey to the Isle of the Blessed.