The Exclusion Crisis ran from 1679 through 1681 in the reign of King Charles II of England, Scotland and Ireland. The Exclusion Bill sought to exclude the King's brother and heir presumptive, James, Duke of York, from the thrones of England, Scotland and Ireland because he was Roman Catholic. The Tories were opposed to this exclusion while the "Country Party", who were soon to be called the Whigs, supported it.
In 1673, when he refused to take the oath prescribed by the new Test Act, it became publicly known that the Duke of York was a Roman Catholic. His secretary, Edward Colman, had been named by Titus Oates during the Popish Plot (1678) as a conspirator to subvert the kingdom. Members of the Anglican English establishment could see that in France a Catholic king was ruling in an absolutist way, and a movement gathered strength to avoid such a form of monarchy from developing in England, as many feared it would if James were to succeed his brother Charles, who had no legitimate children. Sir Henry Capel summarised the general feeling of the country when he said in a parliamentary debate in the House of Commons of England on 27 April 1679:
From popery came the notion of a standing army and arbitrary power... Formerly the crown of Spain, and now France, supports this root of popery amongst us; but lay popery flat, and there's an end of arbitrary government and power. It is a mere chimera, or notion, without popery.