Archwizard

An archwizard was an arcane spellcaster. The first archwizard was Ioulaum of Netheril, who achieved this status when he created the first flying city in Faerûn, Xinlenal, through the use of a mythallar, another of Ioulaum's creations. The moment Xinlenal was afloat, every Netherese arcanist of sufficient power strove to make their own.

As a Prestige Class
An archwizard was an arcane spellcaster, almost invariably a wizard, who had their own city with a mythallar. In 1479 DR, only Thultanthar had an archwizard who met ancient Netheril's requirements. At this time, archwizards were known as archmages, with little or no relation to Netherese arcanists.