Deheubarth (literally, "south part") was a south-western kingdom or principality of medieval Wales. History Deheubarth was founded Circa. 920 by Hywel Dda ("Hywel the Good") out of the territories of Seisyllwg and Dyfed, both of which had come into his possession. Later on the Kingdom of Brycheiniog would also be added to its territorial boundaries. The chief seat of the rulers of Deheubarth and its traditional capital was at Dinefwr (although Carmarthen and Cardigan also served as the Kingdoms… (More on Deheubarth)