Arthaban grew up under the guidance of Archmage Arugal, who found him as an infant. He learned the ways of magic from Arugal, and apparently he was a natural. Later in his life, he left his master and met Deloim with who he became very good friends.
The construction of the Greymane wall
When the Greymane wall was made, Arthaban decided to go back to Gilneas, to live there. He had a good life, until the worgen came, due to his former master Arugal. He felt guilty for the fact that the rampaging worgen devoured every human in their path, so he joined forces with Vincent Godfrey and used his magical powers to hunt down the worgen. This killing spree was brought to an ironical end, when he himself was turned into a worgen.
When Gilneas was evacuated, he was reunited with his friend Khuilhin, son of Deloim. Though he keeps his worgen form a secret, since Khuilhin seems still filled with hatred for the creatures that rampaged his friend's homeland.