The County of Dyfed
Dyfed was one of several Welsh kingdoms that emerged in South West Wales in 5th century following the departure of the Romans. The kingdom was the former lands of the Déisi, later subsumed into the principality of Deheubarth.
The Déisi were a class of people in ancient Ireland. In Latin, the land of the Déisi was Demetae, which eventually evolved into Welsh as Dyfed.
Dyfed covers approximately the same geographic extent as the ancient Principality of Deheubarth, excluding the Gower Peninsula and the area west of the River Tawe.
Dyfed is now a Preserved County of Wales used for the ceremonial purposes of Lieutenancy and Shrievalty. It was created on 1 April 1974 from the administrative counties of Cardiganshire, Carmarthenshire, and Pembrokeshire, and used for local government and other purposes between 1974 and 1996.
