The Esteemed and Ancient College of Arcanists (called so many things in so many places that it's most often simply referred to as The College) is a system of institutions founded under the auspices of the Linaean Emperor Manos the Glorious.  Where prior rulers had seen the power of arcane magic as, at best, an unpredictable weapon, Manos saw it as a way to enrich and educate the Empire and her citizens beyond what mere toil could ever hope to accomplish.

And so he founded the first of the Arcane Colleges a day's ride from Linaea itself, inside of a steep-sided gorge, surrounded by guard posts.

He was an optimist, not a fool.

But no (decisive) calamity struck the College, and over the centuries a College sprung up in most of the more established provinces, until it became a mark of pride and distinction to have one in your city.

With the Empire's crumbling collapse, however, regional biases began to well up again.  Any time a famine, plague, or giant rampaging nightmare beast appeared and The College failed to stop it, they were liable to be blamed for it.  Especially the latter for some reason.  Accordingly, the general populace of many nations (especially those dominated by humans, with their short memories) has grown to distrust Arcane magic, and angry mobs have left roughly half of the former Colleges in ruins.