Edward of Norwich, 2nd Duke of York by a French chronicler to have betrayed to the king a conspiracy at the end of 1399 by a group of Richard II's former favourites who planned to murder Henry IV and his sons at a jousting tournament at Windsor Castle on 6 January 1400. But according to James Tait, contemporary English sources that describe the conspiracy make no mention of Edward, and his role in it is open to question. In October 1400, the king made Edward Keeper of North Wales, and on 5 July 1401, his lieutenant in Aquitaine. On 1 August 1402, Edward's father died, and he
Castles and Town Walls of King Edward in Gwynedd to conduct negotiations with the king. Henry Percy took an oath in the castle chapel to protect the king if he agreed to leave the castle, but when Richard left he was promptly taken prisoner, and was taken away to die later in captivity at Pontefract Castle. Tensions between the Welsh and the English persisted and spilled over in 1400 with the outbreak of the Glyndŵr Rising. At the start of the conflict, Harlech's garrison was badly equipped, and Conwy had fallen into disrepair. Conwy Castle was taken at the start of the conflict by two Welsh brothers, who took