Greyhawk Canon
The World of Greyhawk was based on Gary Gygax's campaign map of The Great Kingdom for a medieval miniatures campaign for “The Castles and Crusades Society” several years before the creation of D&D. Gary Gygax used it for his first D&D campaign and in 1979 published the first public version of the campaign setting. It included the Darlene Map and a booklet gazetteer. Later, in 1983, another version was published with the same map and a more complete description of the lands, again by Gygax.
After this point, subsequent products, events and descriptions were published, advancing the timeline and changing much of the territory. There was even a “Living Greyhawk” Campaign, whcih was sort of a league-play and tournament version in the early 2000's.
I mention this history to set a few parameters of lore and canon for this campaign.
1–Darelne Map The only thing that's absolutely canon is the Darlene Map. Anything that's on the map is in the world.
2–Gary Gygax's description of the world, but not necessarily the game mechanics implications, are MOSTLY taken as basic common knowledge and are likely to be able to be counted on as mostly real (although exceptions may happen). Let's keep the city and town populations as written, but only use the national populations as relative numbers for comparing two nations.
3–Other online material, especially from the post Common Year 576 era are not to be relied upon or counted on in the least, especially anything to do with the Greyhawk Wars or their aftermath or anything from Living Greyhawk. So, be careful of most internet material on these places and peoples, they are likely to be not applicable.
If you want detailed descriptions of the world that are close to canon, look at this document. totally_not_a_copy.pdf