As I've already mentioned in The City You Don't Remember, Remembers You Still the rivalry that Dyvers has with Greyhawk colors a lot of the way that the people of Dyvers see themselves and the way that they see the world, but there may be an underlying reason why they've been so willing to engage with Greyhawk that goes a bit deeper. In the Living Greyhawk Gazetteer Dyvers' history begins as follows:
". . . Long a trade port, Dyvers was also the capital of Aerdy's Viceroyalty of Ferrond. In that role, it served as a welcome port to goods and travelers who braved the unexplored shores of the Nyr Dyv. The palace of the viceroy rivaled that of his colleagues in the west, and its domed central structure and austere stone towers have long been cited in travelogues as among the finest examples of Oeridian architecture.
By 254 CY, the degradation of the Great Kingdom had grown too profound for the lords of the west. In that seminal year, the heir to Viceroy Stinvri was proclaimed King Thrommel I. The Viceroyalty of Ferrond was no more. In its place stood a vast independent kingdom, Furyondy, with Dyvers as its cosmopolitan capital.
Dyvers had been the region's capital for more than 150 years. Despite the gradeur of the palace grounds and the long tradition, however, Thrommel and his newly installed court desired a grander seat for their new realm. A short time after the coronation, plans were drawn for a new capital, Chendl, far to the north. By 288 CY, the king had abandoned the "City of Sails" for his new seat of power, the meticulously crafted architectural wonder of Chendl . . ." (Holian, 41)
". . . In recent years, Dyvers has gained the unfortunate reputation of being a good place to "get lost" - or, rather, to lose one's pursuers. After the Horde of Elemental Evil was routed at Emridy Meadows, some adherents to darkness who did not flee to the Wild Coast instead traveled north to Dyvers, bolstering the criminal element in the city. . . ." (Holian, 41)