Owain ab Gruffydd, lord of Glyndyfrdwy (c. 1359 – c. 1415), or simply Owain Glyndŵr or Glyn Dŵr (pronounced [ˈoʊain ɡlɨ̞nˈduːr], anglicized to Owen Glendower), was a Welsh leader who instigated a fierce and long-running yet ultimately unsuccessful war of independence with the aim of ending English rule in Wales during the Late Middle Ages. He was the last native Welshman to hold the title Prince of Wales (Welsh: Tywysog Cymru).
Glyndŵr was a descendant of the Princes of Powys through his father Gruffudd Fychan II, hereditary Tywysog of Powys Fadog and Lord of Glyndyfrdwy, and of those of Deheubarth through his mother Elen ferch Tomas ap Llywelyn ab Owen. On 16 September 1400, Glyndŵr instigated the Welsh Revolt against the rule of Henry IV of England. The uprising was initially very successful and rapidly gained control of large areas of Wales, but it suffered from key weaknesses – particularly a lack of artillery, which made capturing defended fortresses difficult, and of ships, which made rebel-controlled coastlands vulnerable. The uprising was eventually suppressed by the superior resources of the English. Glyndŵr was driven from his last remaining strongholds in 1409, but he avoided capture; the last documented sighting of him was in 1412. He twice ignored offers of a pardon from his military nemesis, the new king Henry V of England, and despite the large rewards offered, Glyndŵr was never betrayed to the English. His death was recorded by a former follower in the year 1415.
With his death Owain acquired a mythical status along with Cadwaladr, Cynan and Arthur as a folk hero awaiting the call to return and liberate his people. In William Shakespeare's play Henry IV, Part 1, the character of Owen Glendower is a wild and exotic king ruled by magic and emotion. In the late 19th century, the Cymru Fydd movement recreated him as the father of Welsh nationalism.