Powys Fadog or Powys Gogledd was the northern portion of the former princely realm of Powys which split in two following the death of Madog ap Maredudd of Powys in 1160. The realm was divided under Welsh Law between his two sons; Owain Cyfeiliog who inherited the south (see Powys Wenwynwyn) and; Gruffydd Maelor I who inherited the north.

Gruffydd Maelor I received the cantrefs of Maelor and Ial as his portion and later added Nanheudwy, Cynllaith, Glyndyfrdwy and Lower Mochnant. This northern realm became known as Powys Fadog after 1191.

Princes of Powys Fadog

• 1160 - 1191 Gruffydd Maelor I

• 1191 - 1236 Madog ap Gruffydd I

• 1236 - 1269 Gruffydd Maelor II

• 1269 - 1277 Madog ap Gruffydd II

Madog ap Gruffydd II was defeated and killed in war with Gwynedd. His heirs were forced to accept the overlordship of Llywelyn ap Gruffydd

• 1277 - 1289 Gruffydd Fychan I

• 1289 - 1304 Madog Cripell

• 1304 - c.1350 Gruffydd Fychan II

• 1350 - c.1416 Owain ap Gruffydd

• 1416 - ? Maredudd ab Owain Glyndwr