In 1555, Queen Mary began permitting the burning of Protestants for heresy, and some 220 men and 60 women were executed before her death in 1558. These persecutions contributed to the ultimate victory of the English Reformation, though Pole's involvement in these heresy trials is disputed. Pole was in failing health during the worst period of persecution, and there is some evidence that he favoured a more lenient approach: "Three condemned heretics from Bonner's diocese were pardoned on an appeal to him; he merely enjoined a penance and gave them absolution." As the reign wore on, an increasing number of people turned against Mary and her government, and some people who had been indifferent to the English Reformation began turning against Catholicism. Writings such as John Foxe's 1568 "Book of Martyrs", which emphasised the sufferings of the reformers under Mary, helped shape popular opinion against Catholicism in England for generations.