The kingdom of Powys covered the eastern part of central Wales. Regions included Builth and Gwerthrynion. It is important to note it was occupied by the Irish for a few years by Banadl (usually given as 441–447 AD), and was united with Gwynedd in 854 upon the death of Cyngen ap Cadell by his nephew Rhodri Mawr.
From 1160 Powys was split into two parts. The southern part was later called Powys Wenwynwyn after Gwenwynwyn ab Owain "Cyfeiliog" ap Madog, while the northern part was called Powys Fadog after Madog ap Gruffydd "Maelor" ap Madog.