The discovery of elemental magic is lost to history. It’s always been a part of life on Ird.
Casters able to manipulate the element of Light had a profound effect on Ird. Because of their healing powers, only grave misfortune or the most virulent diseases and poisons would bring about death before old age could do the same. Even then, some of the most powerful users of Light would be able to restore life to another, but this was at great peril to themselves.
Light casters were said to be gifted with The White Hand. Long before the Tiers and even before Misvic Forge, these casters were revered and they gathered together in hospices and eventually formed the Followers of the White Hand.
The Followers of the White Hand is almost a religious order with its own trappings, rituals and traditions. The head of the Followers in each major city after the Fall is referred to as the Archbishop of that city. Below the Archbishop are the Bishops, Priest and Brothers and Sisters of the White Hand.
The Followers attempt to actively recruit anyone who shows a talent for manipulating Light. At some points in history, most notably after the Fall, this recruitment went beyond an attempt to convince and became conscription. The current Followers are trying to recover from this stain on their reputation. Even so, there are some among the Followers who feel that all who can use Light should be among their ranks.