The Igneous Delta was a wasteland that spread from Duardinia to the acidic ocean. Though the location was once inhabited by various civilizations, it was conquered by the forces of Khorne, such as the Goretide and Bloodsecrators.
It was in the Igneous Delta where Sigmar first decided to send his Stormcast Eternals to liberate the Gate of Azyr. The forces included the Thunderstrike Brotherhood, led by Lord-Celestant Vandus Hammerhand and the Heavenhost, led by Lord-Celestant Sargassus. The mighty lord of Khorne, Khorgos Khul, and his ravening Goretide stood in their way. This was the first true battle the forces of Khorne had in centuries and they were soundly defeated. Learning of the Bloodbound's defeat, conquered people of the Igneous Delta rose up against the forces of Khorne. This battle was considered the beginning of the Realmgate Wars.