Stormwind Mage Quarter had not originally existed. Although humans had many mages, the vast majority chose to go to Dalaran and join the Kirin Tor.
Dalaran possessed humanity's finest magical resources and traditions, where studying magic yielded twice the result with half the effort. Moreover, proud human mages naturally considered themselves even more distinguished than noble knights, so most were unwilling to join the various kingdoms.
Previously, the human kingdoms generally had only a small number of court mages. These court mages were hired by royal families at great expense, after all, mages needed vast amounts of gold to purchase all kinds of magical materials, and a mage tower was even more costly. The most famous among the court mages of the human kingdoms was Aran, father of Medivh, the Astral Mage.
Stormwind had been able to expand its court mages into Royal Mages and renovate the Mage Quarter only because Archimonde the Defiler had descended upon Azeroth and destroyed Dalaran.
The Scourge's rampage brought millions of people to Stormwind. The Burning Legion's invasion, meanwhile, drove thousands of elite Dalaran Kirin Tor mages south in search of refuge.
What kind of man was Varian Wrynn, High King of the Alliance? His ambition and wisdom were unquestionably among the finest of all Alliance kings. Thus, when he took in those displaced Dalaran Kirin Tor mages, he set one condition: they had to relinquish their identities as Dalaran Kirin Tor mages, swear loyalty to Stormwind instead, and become Stormwind Royal Mages.
After gaining Stormwind Royal Mages, Varian Wrynn, High King of the Alliance, did not mistreat them. To display his generosity, he had the Stonemasons' Brotherhood build a great number of mage towers in the Mage Quarter, making it no less impressive than Dalaran.
Only then did those proud Dalaran Kirin Tor