Age of Guilds is a period in the history of magic
As the use of magic became more prevalent, so did the problems inherent in its use. Since magic had become available to people in all professions, conflicts arose. One famous issue involved the question of whether the plumber's FIZMO spell could be sold as a digestive aid by physicians. The issue came to a head in the aftermath of the Endless Fire of 773 GUE, so named because it burned for 4 weeks after destroying the city of Mareilon. It was later found to have been started by a civil servant who thought he was casting the ZEMDOR spell but who, instead, cast the ZIMBOR spell ("turn one really big city into lots of tiny, little ashes").
This led Lord Dimwit Flathead to issue a series of 5,521 edicts over the following few weeks, which had the effect of severely limiting access to magic (and, incidentally, lawyers). Henceforth, all magic was entrusted to the various Guilds of Enchanters, which by now existed in many small communities. Each Guild, whose elders comprised the so-called Circle of Enchanters, was empowered to form schools for the training of new Enchanters. This official sanctioning of the Guilds led to the formation of numerous other chapters, with membership in the various Guilds in excess of 2,000 by the year 800 GUE. Despite the fall of the Great Underground Empire in 883 GUE under the feeble-minded reign of Wurb Flathead, the Guild of Enchanters remains virtually unchanged in character today.