The Tieflings of Corinth hold no great kingdoms, or vast empires. Not anymore. Once, a very long time ago there was a "homeland" for the race, but their empire crumbled long ago. Now the "devil-men," as they are oft-times referred to are largely vagabonds. They settle where they find a livelihood. Many of them become traders or adventurers. Next to humans, they are likely to be the race driven most by curiosity.
Despite tieflings' demonic appearance, many of them are quite personable. Evil members of the race are encountered, but no more than a member of any other given race. On the whole they are emotionally very much like humans, which has given rise to the popular theory that once, ages ago they were. Most tieflings themselves seem not to care. It's rare to find any tieflings still living that remember more about their ancient kingdoms than simple tales and references in historic texts. The land they once ruled is a wasteland now, given over to demonic presence as well as the undead. It's said that at the center of this dread place, where the capitol of the tiefling empire once stood there is now a city that is a blight on the world itself. Even the demons that inhabit the land now don't dare to go there. Whether this is true or not, none can say.