Camaris, wielder of the sword Thorn, was Prester John's best knight and best friend, and in a certain way, his foil. He first encountered Prester John in battle as his foe in a war to resist John's conquering of Nabban. He was 15 at the time and weilding Thorn, John was 40 and wielding Bright-Nail (Minneyar, aka Memory). When Camaris entered the battle he wreaked havoc among John's Erkenguard until he met John himself. The two fought for a while at stalemate, John eventually winning due to a swift kick to Camaris' groin while Camaris was showing him mercy instead of delivering a death-blow to the neck. In turn, John spared Camaris and the two became best friends.
Both men were considered the best knights of their time along with Tallistro of Perdruin, but ultimately Camaris' skill in battle outweighed everyone and he became known as the mightiest and most skilled warrior ever to walk the face of Osten Ard. While Prester John relished war, Camaris always found it a necessary evil and a burden. Although his skills and status were undisputed, he hated having to fight and kill. His reputation constantly earned him challenges that he did not want. After Prester John's wife, Ebekah died giving birth to Josua, Camaris left his position at the Hayholt court and, according to rumors, he drowned himself in the sea.
Camaris survived but suffered a severe case of amnesia and lost his ability to speak. He remained an anonymous simpleton-mute for forty years in Kwanitupal at an inn called "Pelippa's Bowl" under the name Ceallio. He remained undiscovered until Duke Isgrimnur, on orders from Dinivan in Nabban, discovered him at the inn while on his journey there to rendezvous with an unspecified ally of the Leage of the Scroll.
Duke Isgrimnur recognized him immediately and tried to bring Camaris back to sanity but was unsuccessful. Astoundingly, Isgrimnur noted that although Camaris had aged 40 years, he had lost absolutely none of his size, agility, speed, or strength. (This came to be verified later in combat.) Staying at the Inn was Tiamak, the person Isgrumnur was instructed to meet. They waited together for a few months in hopes the Princess Miriamele would show up, as Dinivan had told Isgrimnur she would. When Miriamele finally arrived, she was being pursued by Nabbanai soldiers under the guidance of Aspitis. In extreme haste the Miriamele, Cadrach, Isgrimnur, Tiamak and Camaris escaped into the Wran on a boat and went through several trials before making their way north into the Thrithings.
In his cursed-state, Camaris retained his fighting ability. When his group was waylaid by Aspitis, Camaris unwillingly fought him. Although he was sluggish and fighting almost 100% defensively, he thrashes Aspitis. After Camaris unwittingly delivers the group, they make their way north to Sesuad'ra and rendezvous with Josua Lackhand and his growing army. No one recognizes Camaris except for Isgrimnur and Towser, both of whom knew the living-legend very well. The very night Camaris arrives, Towser dies. He was said to have grown pale and whispered "I swear I told no one!" before retreating into his tent and passing away.
As an epic climax to the first installment of To Green Angel Tower, it's discovered that Camaris is the subject of an intricate prophecy. He is given Thorn, his Horn, and brought to Deornoth's grave where he is cured by Josua of his madness and regains 100% of his memories and functionality. He is slowly reintegrated into current events and teaches Simon some fighting and general knight-knowledge.
He leads Josua's army into Nabban where he proves to have lost absolutely none of his prowess in battle. Wherever he goes, allies rally and enemies die. At one point he cuts a man in half at the waiste through the man's armor. By introducing Camaris to key figures who recognize him, Josua eventually gains a huge following in Nabban with Camaris at the head of the army. Benegaris recognizes his doom and fights Camaris in a one-on-one match; the match is close but Benegaris falls to his Uncle's sword. Camaris then becomes the uncontested ruler of Nabban.
At this point, Thorn begins calling Camaris to Green Angel Tower. The armies begin to move but Camaris is heavily distraught by the voices he is hearing from Thorn. He also has a huge weight on his shoulders...some secret sin that he confesses to Josua on the ships during the voyage to Erchester.
At the seige of the Hayholt, Camaris can't handle the voices anymore and infiltrates the castle through the ancient Sithi tunnels. Josua and the Sithi pursue him. Eventually Camaris makes his way to the top of Green Angel Tower, and is compelled by the power of Thorn to assist in the release of the Storm King through Pryrates ritual. Camaris resists as much as possible but can't overpower the sword.
When the ritual is thwarted by Simon, Camaris catches on and assists, bringing destruction to the Storm King. He is assumed dead after the fall of the tower, but Josua (Also assumed dead) escapes and reveals to Simon and miriamele that Camaris escaped and carried Josua to safety. Josua rescinds his claim to the throne, saying Simon has more of a right anyways since Josua's father was Camaris, not Prester John. (Camaris' confession) He vows to find Camaris, who's disappeared again.