Tudur ap Gruffudd (1365-1405), also known as Tudor de Glendore or Tudor Glendower, was the Lord of Gwyddelwern, a junior title of the Princely house of Powys Fadog, and was the younger brother of Owain Glyndŵr, the Welsh rebel leader crowned Prince of Wales (anglicized by William Shakespeare as 'Owen Glendower' in his play Henry IV). His father was Gruffydd Fychan II, the hereditary Prince of Powys Fadog and previous Lord of Gwyddelwern. Along with his brother, Owain Glyndŵr, Tudur was a member of the Royal House of Mathrafal.