Arthur Foundling is a heroic squire in the Army of Callow, that during the Hainaut Campaign became the Squire.
Arthur grew up as an orphan in Laure at Queen Mary’s Home for Errant Boys, close to the orphanage that Catherine Foundling grew up in. At age 13 he ran away to join the Callowan knights as a squire.
The Hainaut Campaign
At age 16, Arthur transitioned into the Squire at the Battle of Maillac's Boot where he lost both his knight mentor and his boyfriend on the same day.
Being in an unusual position, Arthur is technically under the authority of Hanno the White Knight as a hero, but also is part of the Army of Callow that's lead by the Black Queen Catherine Foundling. With some arrangements with Hanno, Cat has seen to Arthur's care and introduced him mainly to heroic Names she approved of before Hainaut.
The Praesi Campaign
During the Grand Alliance's invasion of the Dread Empire of Praes (primarily by the Army of Callow), Arthur started a pattern of three against the new Black Knight Marshal Nim. However, on the third encounter, instead of defeating Nim he chose to fight beside her against a foe he considered unjust, maturing into the Knight Errant in the process.
Catherine describes Arthur with the following: The boy was almost offensively heroic in appearance, like some higher power had taken the mould of ‘young hero’ straight of out Callowan culture and poured materials into it. Dark-haired and blue-eyed, with an angular face and strong shoulders, I could already see he was going to grow into a handsome man.
His hair is black.
Sapan: Arthur and the apprentice has been described as "thick as thieves", and often are shown as a duo spending time together, or fighting side by side, when they appear.