Profile of Queen Mary I, the Catholic daughter of Henry VIII and Catherine of Aragon, whose persecution of Protestant 'heretics' unleashed a reign of terror on a country already in turmoil. Stung by her father's callous treatment of her mother, she set out to operate a policy of religious toleration when she succeeded to the throne in 1553. However, opposition from enemies real and imagined called for a more ruthless approach and soon hangings and burnings became daily occurrences, earning her the soubriquet Bloody Mary