The Kingdom of Heidel ruled over the Serendia territory with the seat being in Heidel City before the army of the Republic of Calpheon took its king prisoner. King Crucio was only released when he agreed to the three demands of Calpheon:
- Heidel cannot mass forces or field their army.
- All diplomacy and trade is to be conducted through Calpheon.
- Serendia's Black Stones become Calpheon property.
Besides these rules it is unclear if Heidel is now a vassal state or still a sovereign kingdom. The colors of Heidel's army are white and green.