In the World of Greyhawk boxed set the City of Dyvers has a population of 53,000 when you take in not only the city itself but its surrounding territory. By the time the Living Greyhawk Gazetteer is published the city has grown in population to 128,000 – more than doubling the original number!
What drove this growth trend?
What we know about that growth tends to be a bit disjointed as it goes across several sources so I’m going to simplify the information by using only a single source: Slavers. This adventure provides us with a rather detailed look at the city, and a brief history; but more than that, it represents a glimpse into the reorganization of the setting by Wizards of the Coast as they moved from Second Edition into Third Edition and once again used the setting as their primary one.
Slavers is set 10 years after the events of the original Scourge of the Slave Lords adventures. This would put Slavers at about 590 CY, or about six years after the Greyhawk Wars. In the text the first influx of refugees began coming into the city after the fall of the Temple of Elemental Evil in 569 CY.
The Greyhawk Wars (582 -584 CY) saw even more refugees fleeing to the city. Throughout the conflict the city of Dyvers seemed to be a safe haven for people fleeing the conflict. Around 583 CY the Shield Lands were invaded by Iuz and Dyvers saw a great influx of refugees. Then Turrosh Mak and his orcish armies formed the Pomarj which drove more refugees to the city. By the fall of 584 CY the city even found refugees fleeing there from Greyhawk after the Old City fire.
Why did so many flee here?
It may well be that the driving force behind the movement to Dyvers is because it’s free to enter the city. Dyvers also has a few other factors that might make it more appealing as a destination than the City of Greyhawk. Dyvers has a robust industrial and merchant base with a huge bazaar that surrounds the city most days of the year. It also features a population that is more accepting, with less restrictions, and easier social movement than the more structured Greyhawk.
Something to ponder going forward.