Hywel Dda University Health Board (HDUHB) is the local health board of NHS Wales for the west of Wales. Established on 1 October 2009 from the merger of the Hywel Dda NHS Trust, the Pembrokeshire Local Health Board, Ceredigion Local Health Board and Carmarthenshire Local Health Board. The local health board is named in honour of historic south west Wales king Hywel Dda. Hywel Dda University Health Board provides healthcare services to a total population of around 385,615 throughout Carmarthenshire, Ceredigion and Pembrokeshire. The headquarters of Hywel Dda is based in Hafan Derwen, St David's Park, Carmarthen, Wales. Hywel Dda University Health Board is the operational name of Hywel Dda Local Health Board.