In the World of Greyhawk campaign setting for the Dungeons & Dragons fantasy role-playing game, the Iron League is an affiliation of states that opposed the Great Kingdom of Aerdy. It formed in late 447 CY as a reaction to Ivid V becoming Overking of Aerdy. Idee, the Free City of Irongate, and Onnwal were charter members of the organization.
The Lordship of the Isles later joined the Iron League in 448 CY, and the County of Sunndi in 455 CY. Sunndi has urged the town of Dullstrand to join the league, but as of the current campaign setting of 590 CY, Dullstrand has remained aloof.
References
Iron League Wikipedia(Text) CC BY-SA