The Glyndŵr rebellion was a Welsh rebellion led by Owain Glyndŵr against the Kingdom of England during the Late Middle Ages. During the rebellion's height between 1403 and 1406, Owain exercised control over the majority of Wales after capturing several of the most powerful English castles in the country, and formed a parliament at Machynlleth. The revolt was the last major manifestation of a Welsh independence before the annexation of Wales into England in 1543.

Owain ap Gruffydd, commonly known as Owain Glyndŵr or Glyn Dŵr, was a Welsh leader, soldier and military commander in the Late Middle Ages, who led a 15-year-long revolt with the aim of ending English rule in Wales. He was an educated lawyer, forming the first Welsh parliament under his rule, and was the last native-born Welshman to claim the title Prince of Wales.