In the year 1 BE, Abaddon gave the ability to use Magic to the sentient races of Tyria. However, this gift was given too freely, resulting in immediate and bloody wars. The leader of the human kingdoms in Tyria at the time, King Doric, traveled to Arah to seek audience with the gods and begged at their feet for their compassion and to take back their gift of magic. The gods heard his plea and created the bloodstone, which limited the use of magic that the races could use, and then split it into five portions that represent the four schools of magic and a keystone to forever seal away the full power of magic and the mistake that was made by giving too much power to mortals. After the creation of the bloodstones, the gods plunged the giant stones into the largest volcano of the Ring of Fire Island Chain. Soon after, they left the world in the act known as The Exodus.
Thus in modern times, beings on Tyria are unable to harness all the potential power that magic offers; in order to make full use of the original gift, they must work together. Magic is made up of four principle schools: Preservation, Destruction, Aggression, and Denial. In turn, each magic-using profession is linked to a single school. The specific school each profession utilizes is not completely certain.
There are a few cases of magic being used before the Exodus, when it was given to the races of Tyria. The most recent of them takes the form of the Ritualist profession. Early Canthan Ritualists were able to call upon their ancestors to produce magical effects; the introduction of magic allowed the profession to become stronger, using both the old methods and the new ones. Historical records claim that what ancient Ritualists used was not magic but merely had similar effects.
Older cases of magic are not clear on when they occurred, and in some cases the source is dubious. Ancient Jotun lore claims that magic existed when the Elder Dragons were last awake, being chaotic and uncontrollable. It is also said in Jotun lore that their now-fallen civilization once held powerful magic before the gods arrived on Tyria, though some sources claim it to be a gift from the gods.
The last case of magic existing before the gods granted it is the war between the Mursaat and the Seers which occurred before the gods and humanity arrived on the world. The Seers were defeated through the spell Spectral Agony, showing that the Mursaat had magic independent of the gods.