User blog comment:Spritydove/Deeper Thought into the Civil War/@comment-4692902-20120616075537/@comment-80.216.219.47-20120620052003

Well, "The Legend of Red Eagle" says the Forsworn had kingdoms in the Reach when they started venerating Hagravens.

And suggests a date 1E 1030, but mentions that it is likely a later anachronism