Whiggism or Whiggery is a political philosophy that grew out of the Parliamentarian faction in the Wars of the Three Kingdoms (1639–1653) and was concretely formulated by Lord Shaftesbury during the Stuart Restoration. The Whigs advocated the supremacy of Parliament (as opposed to that of the king), government centralisation, and coercive Anglicisation through the educational system. They also staunchly opposed granting freedom of religion, civil rights, or voting rights to anyone who worshipped outside of the Established Churches of the realm. Eventually, the Whigs grudgingly conceded strictly limited religious toleration for Protestant dissenters, while continuing the religious persecution and disenfranchisement of Roman Catholics and Scottish Episcopalians. They were particularly determined to prevent the ascension of a Catholic heir presumptive to the British throne, especially of James II or his legitimate male descendants and instead granted the throne to the Protestant House of Hanover in 1714. Whig ideology is associated with early conservative liberalism.
Beginning with the Titus Oates plot and Exclusion Crisis of 1679–1681, and the Glorious Revolution of 1688–1689, Whiggism dominated English and British politics until about 1760, after which the Whigs splintered into different political factions. In the same year, King George III was crowned and allowed the Tories back into the Government. Even so, some modern historians now call the period between 1714 and 1783 the, "age of the Whig oligarchy".