 In the 18th and 19th centuries, with more scientific methods becoming available more refined ceramics were produced led by the Cambrian Pottery (1764–1870, also known as "Swansea pottery") and later Nantgarw Pottery near Cardiff, which was in operation from 1813 to 1822 making fine porcelain and then utilitarian pottery until 1920.Portmeirion Pottery, founded in 1960 by Susan Williams-Ellis, daughter of Clough Williams-Ellis, creator of the Italianate village of Portmeirion, Gwynedd, is based in Stoke-on-Trent, England.The Flag of Wales incorporates the red dragon () of Prince Cadwalader along with the Tudor colours of green and white.