A study of Puritan iconoclasm in England during the period of the civil wars and Interregnum, this thesis looks at the reasons for the resurgence of large-scale iconoclasm a hundred years after the break with Rome. Initially a reaction to the emphasis on ceremony and the 'beauty of holiness' under Archbishop Laud, the attack on recent 'innovations' introduced into the church (such as images, stained glass windows and communion rails) developed into a drive for further reformation led by the Long Parliament. Increasingly radical legislation targeted not just 'new popery', but pre-reformation survivals and a wide range of objects including some which had been acceptable to the Elizabethan and Jacobean church (for instance organs and vestments). Parallel to this official movement was an unofficial one, undertaken by Parliamentary soldiers during the war, whose iconoclastic violence, particularly against cathedral churches, became notorious. The significance of this spontaneous action and the importance of the anti-Catholic and anti-Episcopal feelings that it represented is examined. So too is the promotion of such feeling and of the cause of the reformation of images through printed literature (both popular and learned). A detailed survey is made of parliament's legislation against images, and the work of its Committee for the Demolition of Monuments of Superstition and Idolatry, headed by Sir Robert Harley. The question of how and how far this legislation was enforced generally is considered, with specific case studies looking at the impact of the iconoclastic reformation in London, the cathedral churches and at the universities.