John Locke (1634–1704) was born during the build-up to the English Civil War, which culminated in 1649 with the execution of the Stuart king Charles I and the dissolution of the House of Lords. During the Interregnum period of 1649–1660, England reinvented itself as a Commonwealth. In 1660, the Restoration period began as Charles’s son Charles II reclaimed the monarchy’s former control over both church and state institutions. Locke’s early papers suggest that he welcomed these changes. These papers also reveal his sympathy with the concept of a state-appointed (“Anglican”) religion, indicating that he still identified with the orthodoxy of his youth. He would almost completely reverse these views in later years.

The seeds of Locke’s opinions on religion and government were planted during his childhood. His father’s career had taught him a respect for the law, and his Puritan upbringing imparted him with strong religious convictions. A crucial turning point in his philosophical development was a 1665 trip abroad to Cleves, where he observed a community of different religious sects living together in harmony. This experience may have challenged his ideas about the necessity of state-appointed religion and led to the later writing of his Letters Concerning Toleration (1689). Locke held on to his deep-seated Christianity throughout his life and was disappointed in the public response to his essay, The Reasonableness of Christianity (1695). He did not view his critique of Christianity as a condemnation, but religious leaders disagreed and banned the book.

After a three-year visit to France, Locke returned in 1679 to an England in crisis. Rumors of a plot to assassinate Charles II and install his Catholic brother, James, on the throne had caused upheaval in the government. An insurrection, supposedly led by Lord Ashley (by now the Earl of Shaftesbury), mounted as it became clear that Charles II had no intention of reinstating Parliament. Correctly targeted by Charles II as an influential Whig, Shaftesbury luckily survived a trial for treason and afterward fled to Holland. It is unclear how active Locke was in the affair, but his close friendship with Shaftesbury made him appear dangerous to Charles II. Locke followed Shaftesbury to Holland in 1683. In 1685, Charles II died, and the Catholic James II ascended the throne. In 1688, at the invitation of pro-Parliamentary supporters in England, James’s Dutch brother-in-law William of Orange invaded England in what is known as the Glorious Revolution. James II fled to France as Parliament was reinstated and James’s brother-in-law and sister reigned jointly as King William III and Queen Mary II. Exiles including John Locke were welcomed back to England from Holland.

In his Two Treatises of Civil Government, Locke sought to refute the pro-Absolutist theories of Sir Robert Filmer, which he and his Whig associates felt were getting far too popular. Although not as immediate a challenge, Locke's work also serves as a major counterargument to Thomas Hobbes' Leviathan, in which Hobbes argues in favor of absolutist government to keep people from abusing property and privacy. Many persistent rifts in political theory today stem from the fundamental disagreements between Locke's Second Treatise on Government and Hobbes' Leviathan.

Locke’s Second Treatise on Government, subtitled An Essay Concerning the True Original Extent and End of Civil Government, stands today as an extremely influential work that shaped political philosophy and provided a basis for later political doctrines, such as those set forth in the Declaration of Independence and the United States Constitution.