Elyan

Sir Elyan is the brother of Guinevere and a Knight of Camelot.

Biography
There is no info about what happened to him other then he left home a year before the the series started and the fact that Guinevere, his younger sister didn't know if he was alive or dead.

Elyan and Gwen was reunited when King Cenred kidnapped the two siblings in an attempt to kill Arthur Pendragon. Cenred released Gwen so that she could tell Arthur he had captured her brother. Elyan spent most of his captivity in the dungeon, or with Gwen when she returned with Arthur, Merlin and the treacherous Morgana. Merlin and Arthur managed to rescue the two siblings and returned to Camelot after "saving" Morgana. (The Castle of Fyrien)

He returned to live in Camelot, took over their father's blacksmith shop and lived with his sister.

Elyan was present when Camelot was attacked by an immortal army and attacked Arthur mistaking him for an enemy. He accompanied Merlin, Arthur and Gwaine into Camelot to find his sister. He and Gwaine witnessed Uther Pendragon being dragged towards the throne room and informed Arthur who ordered them to get Gaius, who had also escaped the assault unscathed, into the safety of the forest. Meanwhile Arthur and Merlin witnessed Morgana being crowned Queen of Camelot.

Elyan was later knighted by Arthur and helped him and his allies rescue Uther and the surviving Knights of Camelot.

Personality
Elyan was adventurous, leaving Camelot a year before Merlin arrived and travelled widely. However this meant that he was unable to get into contact with his sister, Gwen who didn't know if he was alive or dead. Elyan loved his sister and hugged her when they were reunited and later came to live with her in Camelot.

He was also cunning enough to be able to hide from Morgause's attack on Camelot, and was the only known person apart from Gaius to escape the attack unscathed.

Abilities
Elyan was a skilled swordsman, as he easily defeated two of Cenreds knights and later became a Knight of Camelot. He also had some skill of a blacksmith, and when he returned to Camelot he reopened and started working at his father's shop.

In the Legends
In Arthurian Legend, Elyan is known as Sir Elyan the White or Helyan le Blanc as the son of Sir Bors and is a Knight of the Round Table. His mother is King Brandegoris' daughter Claire, who tricked Bors into sleeping with her using a magic ring; this is sometimes said to be the only time Bors broke his vow of chastity. When he is older Elyan is accepted as a member to the Round Table, where he becomes known as an excellent knight. Like his father and the rest of his family, Elyan helps his cousin Lancelot rescue Guinevere after their affair is exposed, and joins him in exile.

Elyan's mother Claire is the half-sister of Sir Sagramore; their mother is the daughter of the Eastern Roman Emperor. According to the Lancelot-Grail Cycle, Elyan eventually became Emperor of Constantinople himself.