What is "oeridians"

In the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game, the Oeridians (sometimes called the "Oerid") are a race of humans living in the Flanaess. Having once inhabited the plains of Central Oerik, they moved into what is now known as Ull starting 1,235 years ago; the Oeridians were driven eastward into the Flanaess by orcs and goblins used as mercenaries by the Baklunish Empire and the Suel Imperium. The Oeridians settled in much of the Flanaess, often conquering and assimilating the Flan natives and Suel settlers, though some lands, such as the Sheldomar Valley and Vale of Luna, were settled more peacefully.

The Flanaess' most powerful modern empire, the Great Kingdom of Aerdy, was founded by a warlike Oeridian tribe known as the Aerdi. Other notable Oeridian tribes include the Vollar of modern Veluna and the Nyrondal of Nyrond.

"Unmixed" Oeridians are most commonly found in Furyondy, Perrenland, the Shield Lands, North Kingdom of Aerdy, the See of Medegia, Onnwal, and Sunndi.