At the end of the War of the Hundred Hands, most of the Speakers lay dead, either cut down in the darkness of that terrible night by supposed allies or lying dead with their mechanical titans. In total, ten Speakers escaped the flaming ruins of the Holy Mountain.
Six of them decided to found schools and teach their mystical philosophy. It is through these schools that the High Language was passed onto the first generation of mages.
Akademia Mortos
It is said amidst the wisps and witchlights of the Endless Swamp lies the dread Academy of Shadowfall. Within its stuffy halls and decrepit laboratories, future necromancers practice their corporal craft, reknitting flesh and sundering bone. Founded by the Lich of the Swamp, whose bloodstained name was struck from the records, Shadowfall is found only by the mad and desperate.
Very little is known about necromancy. Its students, when captured alive, swear they adhere to the eldest of the High Arts, taught by the greatest of the Speakers. Most people regard the practitioners of the Art of Flesh and Bone to be lunatics armed with a few cantrips of healing. Then, they see the horde of zombies, skeletons, and grotesques marching to their village, their teeth red and their claws sharp.
Very few, then, doubt the power of necromancy.
Akademia Mekanikos
Haven, the fantastical City of Steam, is known to peasants, wizards, and warriors alike. Its flight paths are meticulously memorized and its appearance is a cause for jubilant celebration, for the artificers dwell within Haven. Their bronze and steel creations, running on a combination of steam and magic, walk the streets and converse with visiting merchants. Founded by Malos the Wise, an eccentric inventor in his twilight years, Haven’s streets are constantly flooded with new and novel inventions, much to everyone’s delight.
Artifice is a well-defined and ever expanding High Art. Countless tomes are dedicated to it and it is quite popular with the rulers of the Known Sky, who often employ a court artificer to advise them. The Art of Craft and Forge, although widely dispersed and known, is quite hard to master; the room for error is wide, with many aspiring artificers winding up injured or dead due to dangerous experiments.
Akademia Oracula
Venture north, they say. Venture further north. No, further. There, you will behold a mechanical mountain, frozen over with time. Trek to the top of the titan and you shall find the Academy of Astra, home of the diviners. They are a secretive sort, with many odd ways and customs. Astra's founder, the eight-eyed Lilethia, weaves a great web of possible futures in the Academy hall, trying her best to direct the flow of time towards her own mysterious ends.
The occult art of divination is often misunderstood. Many people think that a diviner's vision shows them the immutable future, something that will come to pass. In actuality, an oracular vision shows a possible future, that will only come to pass due to a certain set of choices. Because of this misunderstanding, charlatans and false diviners abound, preaching their false visions for a few sigloi.
Akademia Ignitia
As the Wars of Succession rage, the pyromancers of Inferno reach even higher heights of popularity. Born and trained for war, the pyromancers practice for decades in the bronze fortress before being hired by the various armed forces of the Known Sky. Acting as elite magical mercenaries, pyromancers work to amass wealth for themselves and their people.
The Art of Fire and Flame, pyromancy, is known only to a group of aristocratic families known as the Fireblood Houses. They train their children from birth to be the greatest soldiers and only sell the knowledge of their High Art to the wealthiest bidder. Rogue pyromancers are not uncommon and neither are magical spies sent by the other Academies.
Other Magical Arts
The four High Ars described above are the most common mage schools in the Known Sky, but there are certainly more. The druids and aeromancers will probably kill you if their less popular Academies are forgotten and of course there are the four Low Arts, taught by those Speakers who decided not to found schools: gastromancy, galvanism, geomancy, and illusion.