They were sold by their parents in Ghiedi to overseas traders as eggs in order to pay off debts. They were hatched in Ulbach as conscripts to Dattus Filus, but recently escaped after completing basic training.
As they grew, the brothers developed a rivalry, primarily fueled by their vastly different paths, Ghesh for the arcane, and Korvas for the divine. This rivalry probably fueled the development of their opposing dragon breath types later on.
They still fight, usually in a competitive way, each trying to prove to the other that their mastery of their chosen path is better.