Gwilym ap Tudur Rhys and Owain Glyndŵr. As a result, the Tudur brothers began planning an attack on Conway Castle. On Good Friday, 1 April 1401, the brothers and 44 men (which included those who had also been excluded from the pardons) infiltrated the castle. They had pretended to be carpenters, and captured the castle while the guard were in church. Negotiations began for the return of the castle on 13 April, with the king represented by Henry "Hotspur" Percy and Gwilym representing the Welsh forces. After seeking a compromise, which would have resulted in pardons being given to the Welshmen, the king
Glyndŵr Rising campaign in the west, Owain marched down the Tywi Valley. Village after village rose to join him. English manors and castles fell or their inhabitants surrendered. Finally, Carmarthen, one of the main English power-bases in the west, fell and was occupied by Owain. Owain then turned around and attacked Glamorgan and Gwent. Abergavenny Castle was attacked and the walled town burned. Owain pushed on down the valley of the River Usk to the coast, burning Usk and taking Cardiff Castle and Newport Castle. Royal officials reported that Welsh students at Oxford University were leaving their studies for Owain and Welsh