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
Owain Glyndŵr Henry IV refused to pay. Mortimer's nephew could be said to have had a greater claim to the English throne than Henry himself, so his speedy release was not an option. In response, Mortimer negotiated an alliance with Owain and married one of Owain's daughters. It is also in 1402 that mention of the French and Bretons helping Owain was first heard. The French were certainly hoping to use Wales as they had used Scotland: as a base to fight the English. In 1403 the revolt became truly national in Wales. Royal officials reported that Welsh students at Oxford University