The man known as Salaman came from the Great Swamp with an unknown objective.
According to Quelana, around 200 years before the events of Dark Souls 1 she took Salaman as her first pupil. She taught Salaman the art of pyromancy with good results, despite her describing him as a bungling man.
He also received the nickname 'Great Fireball' in regards of the spell he either used or created.
The name 'Salaman' could be made parting from the /Salamander/, which is one of the multiple mythological beings of fire.
Artistically, Hidetaka Miyazaki shared some words in 2011 about Salaman:
Salaman is a character that has an important role, along with the witches of Izalith, in the story of pyromancy rather than in the story of Dark Souls.
Salaman’s story was created to introduce a concept of pyromancy but only his name appeared in the original story.
His visual image has actually been created and he is one of my favourite characters.