Iolaire, the Binder

Before humans walked the Three Sisters, a trio of birds alighted upon Older Sister's shores and beheld the magnificence of untamed land. Draethan, the smallest and wiliest, delighted to think of what games he could play in the mists and tangled wilds of prehistoric Kytheria. Fitheach, a black plumed and somber bird, pondered what mysteries must lie here and wondered at the cycle of life and death always at play. Iolaire, largest and grandest of the birds, took wing and surveyed the land, determined to create a map by which to navigate this new land and tame it.
Though apocryphal (and only maybe false), the figure of Iolaire did live in a prominent human city eight millennia ago. He's credited with forming the basis for high magic training, and is the first recorded human to be born with a Mark, making magic easily accessible to him. Iolaire codified spells, wrote down copious arcane formulae, and even devised levels of initiation for prospective magic users. High magic has waxed and waned in popularity among the humans of Older Sister (it's no accident that the holy judges of more rural tribes are referred to as Draenach, and not one city in Older Sister stands without a temple to Fitheach), but high magic is seen as the mark of educated people, and the magi of Older Sister are sought the world over. Greengate is far from the only magic academy, but it may be the oldest on Kytheria, and the lessons and paradigms formed by Iolaire have weather millennia. Official record notes that Iolaire was approached by the elves at one point and invited to retire to the Rowan Islands at the end of his life, and many believe he lives there still, granted youth by elven magics or ascended to become an elf himself.