"Bloody Mary". Anti-Catholicism among many of the English was not only grounded in their fear that the pope sought to reimpose religio-spiritual authority over England, it was also grounded in their fear that the pope also sought to impose secular power over them in alliance with their arch-enemies France and Spain. In 1570, Pope Pius V sought to depose Elizabeth with the papal bull Regnans in Excelsis, which declared that she was a heretic and purportedly dissolved the duty of all of Elizabeth's subjects to maintain their allegiance to her. This rendered Elizabeth's subjects who persisted in their allegiance to the Catholic Church politically suspect, and it also made the position of her Catholic subjects largely untenable if they tried to maintain both allegiances at once. The Recusancy Acts, which made worship in the Anglican Church a legal obligation, date back to Elizabeth's reign. Assassination plots in which Catholics were prime movers fueled anti-Catholicism in England. These plots included the famous Gunpowder Plot, in which Guy Fawkes and other conspirators plotted to blow up the English Parliament while it was in session. The fictitious "Popish Plot" involving Titus Oates was a hoax that many Protestants believed to be true, exacerbating Anglican-Catholic relations. The Glorious Revolution of 1688–1689 involved the overthrow of King James II, of the Stuart dynasty, who favoured the Catholics, and his replacement by a Dutch Protestant. For decades the Stuarts were supported by France in plots to invade and conquer Britain, and anti-Catholicism persisted. Gordon Riots 1780 The Gordon Riots of 1780 was a violent anti-Catholic riot in London against the Papists Act of 1778. Passed by Parliament, the new law was supposed to reduce official discrimination against British Catholics. Lord George Gordon, head of the Protestant Association, warned that the law would enable Catholics who were serving in the British Army to become a dangerous threat. The protest evolved into riots and widespread looting. Local magistrates feared reprisals and as a result, they did not enforce the riot act. The riots were not suppressed until the Army moved in and dispersed the crowds by shooting them, killing hundreds of rioters. The violence lasted from 2 June to 9 June 1780. Public opinion, especially in middle-class and elite circles, repudiated anti-Catholicism and lower-class violence, and it also rallied behind the government of Lord North. Demands for the establishment of a police force in London were subsequently made.