In 1402, the English Parliament issued the Penal Laws against Wales, designed to establish English dominance in Wales, but actually pushing many Welshmen into the rebellion. In the same year, Owain captured his archenemy, Baron Grey de Ruthyn. He held him for almost a year until he received a substantial ransom from Henry. In June 1402, Owain defeated an English force led by Sir Edmund Mortimer at the Battle of Bryn Glas, where Mortimer was captured. Glyndŵr offered to release Mortimer for a large ransom but, in sharp contrast to his attitude to de Grey, 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 from which to fight the English.