There are nine lores of magic: weatherworking, illusions, healing, transformation, summoning, naming, chanting, patterning, and finding. Most self- or apprentice-taught barely learn half of them, and many just a few. Wizards are skilled, at least minimally, in all of the nine lores.
There were five schools of wizardry cast among the sea, one in each part of the Archipelago. Some were destroyed by trechery or dragons, some are poor in knowledge and others still are finding that the growth of formalized magic is changing their original character.
The ruins of the most prestigious school, the School of Nyekundu, is in the Inner Sea. It was destroyed by dragons over a century ago. It is called the Lost School by mages to this day. The island, Nyekundu, is now just a barren rock and left uninhabited. Most people avoid the island, in the belief that the ghosts of the dead or a perhaps even dragon still exist there.
The Middle Sea hosts the School of Nyeupe. Several surviving mages from Nyekundu made this school their home after the destruction of the Lost School. Over time, their knowledge and their influence has increased the prestige of the school. There is, however, a contingent there who want their school back, apart from the influence of the Lost School.
The Reach Schools are much poorer, in knowledge as well as skill. The School of Njano, in the Deiseil Reach, has few wizards of power as Masters of the school and few wizards of note are thought to have come from there. The one with the darkest reputation is the School of Nyeusi in the Spinward Reach. Forbidden acts are reputed to be taught to the least ethically-challenged of the students.
The School of Kijani in the Widdershins Reach was betrayed by rogue wizards and destroyed by pirates in the last century, leaving no one alive. Kijani, much like Nyekundu, is a barren island and avoided for much the same reason.