Исторические периоды
Kingdom of Seisyllwg (878–899)
878 CE – 899 CE
Area: 4,577 km²
Kingdom of Seisyllwg (900–910)
900 CE – 910 CE
Area: 8,936 km²
Kingdom of Seisyllwg (911–921)
911 CE – 921 CE
Area: 7,936 km²
Kingdom of Seisyllwg (922–946)
922 CE – 946 CE
Area: 14,278 km²
Kingdom of Seisyllwg (947–959)
947 CE – 959 CE
Area: 18,375 km²