Parish Church in 1566, replacing a very unsatisfactory lean-to structure that stood against the north wall of the nave. Many of the monastic buildings became the houses of the new Cathedral hierarchy, although others were demolished. Much of the Cathedral itself had little purpose. The whole East end was used simply as a place for burials and memorials. The cathedral was damaged in the Dover Straits Earthquake of 6 April 1580, where stones fell from the vaulting. Difficult as the sixteenth century had been for the cathedral, it was the period of the Commonwealth that came nearest to destroying both the institution and the buildings. Throughout the 1640s, with Oliver Cromwell's army occupying the Isle of Ely, a puritanical regime of worship was imposed. Bishop Matthew Wren was arrested in 1642 and spent the next 18 years in the Tower of London. That no significant destruction of images occurred during the Civil War and the Commonwealth would appear to be because it had been done so thoroughly 100 years before. In 1648 parliament encouraged the demolition of the buildings, so that the materials could be sold to pay for 'relief of sick and maimed soldiers, widows and children'. That this didn't happen, and that the building suffered nothing worse than neglect, may have been due to protection by Oliver Cromwell, although the uncertainty of the times, and apathy rather than hostility to the building may have been as big a factor. Restoration When Charles II was invited to return to Britain, alongside the political restoration there began a process of re-establishing the Church of England. Matthew Wren, whose high church views had kept him in prison throughout the period of the Commonwealth, was able to appoint a new cathedral chapter. The dean, by contrast was appointed by the crown. The three big challenges for the new hierarchy were to begin repairs on the neglected buildings, to re-establish Cathedral services, and to recover its lands, rights and incomes. The search for lost deeds and records to establish their rights took over 20 years but most of the rights to the dispersed assets appear to have been regained. In the 1690s a number of very fine baroque furnishings were introduced, notably a marble font (for many years kept in Prickwillow church,) and an organ case mounted on the Romanesque pulpitum (the stone screen dividing the nave from the liturgical choir) with trumpeting