Perfeddwlad or Y Berfeddwlad (Welsh for 'Midlands') was a name adopted during the 12th century for the territories in north-east Wales lying between the rivers Conwy and Dee. In the Early Middle Ages, the region as a whole was known as Tegeingl, after the Irish Gaelic tribe Deceangli which inhabited the region since the 1st century BC. This region is also known as Gwynedd Is Conwy (Gwynedd below the [River] Conwy), or Lower Gwynedd; in contrast with Gwynedd Uwch Conwy (Gwynedd above the Conwy), or Upper Gwynedd. The region was composed of the cantrefi of Rhos, Rhufoniog, Dyffryn Clwyd and Tegeingl. As the rivalries between Gwynedd, Powys, and England evolved in the High Middle Ages, the region became known in Welsh as the Y Berfeddwlad, the middle country, as it was situated between upper Gwynedd in the west, England to the east, and Powys to the south.