The Walls of Ostwick
Cult of the Green Flame
The Dalish tell of the elves’ lost Arlathan, and while their tales in some places blatantly contradict the histories we know to be true, some of what they say has inarguable evidence to support it. We do know that their use of the strange arcane flame known as veilfire was widespread, and that in the early days of the Tevinter Imperium they sought to hold on to as much of the elves’ powerful heretical magic as they could.
In the years that followed, as they spread their influence throughout Thedas, they built shrines and temples to their Old Gods and fortresses dedicated to magical experiments all over the southern part of the continent, as far south as Ostagar in Ferelden. Though Our Lady Andraste freed these lands from the Imperium’s grasp, the structures they built remained, and in many places their infernal meddling left the Veil weak and allowed magic to take hold in unnatural ways—for instance, places where veilfire continued to burn endlessly without any mage to maintain it. Over time, various barbarian cults cropped up around these burning altars, mistakenly believing they were signs from the Old Gods, or in some cases that the flames were gods themselves. Stragglers still survive across southern Thedas today.
The so-called “Cult of the Green Flame” is not any kind of organization at all, in truth. It is simply a collective name the history books give to these tiny, separate bands of outcasts and thieves who pay sacrifice to the green fire and hoard Fade-touched artifacts that react to it. Those rare mages who crop up among their numbers are truly dangerous apostates, susceptible as they are to anything the flame manages to attract across the thin Veil during their ecstatic rituals.
—From Before Andrastianism: The Forgotten Faiths, by Sister Rondwyn of Tantervale