Privy Council. Under Edward VI After Edward's accession, Cox's opinions took a more Protestant turn, and he became one of the most active agents of the Reformation. He was consulted on the compilation of the Communion Office in 1548, and the First and Second Books of Common Prayer, and sat on the Commission for the Reform of the Canon Law. As Chancellor of the University of Oxford (1547–1552) he promoted foreign divines such as Pietro Martire Vermigli, and was a moving spirit of the two commissions which sought with some success to eradicate everything savouring of popery from the books, manuscripts, ornaments and endowments of the university, and earned Cox the sobriquet of its 'Canceller' rather than its Chancellor. He received other rewards, a canonry of Windsor (1548), the rectory of Harrow (1547) and the deanery of Westminster (1549). Marian exile Cox lost his preferments on Mary's accession, and was for a fortnight in August 1553 confined to the Marshalsea. He remained in obscurity until after the failure of Wyatt's rebellion, and then in May 1554 escaped in the same ship as Edwin Sandys, to Antwerp. In March 1555 he made his way to Frankfurt. Cox played a major part in what later became known as the troubles at Frankfurt. The exiles had, under the influence of John Knox and William Whittingham, adopted Calvinistic doctrine and a form of service far from the Prayer Book of 1552. Cox stood up for the Church of England service, and the exiles were divided into Knoxians and Coxians. Knox attacked Cox as a pluralist, Cox accused Knox of treason to the Emperor Charles V. The latter proved more effective as a charge: Knox and his followers were expelled, and the Prayer Book of 1552 was restored. Under Elizabeth I In 1559 Cox returned to England, and was elected Bishop of Norwich, but the Queen changed her mind and Cox's destination to Ely, where he remained for twenty-one years. He was an honest, but narrow-minded ecclesiastic, who held what views he did hold intolerantly, and was always wanting more power to constrain those who differed from him (see his letter in Hatfield MSS. i. 308). While he refused to minister in the Queen's Chapel because of the crucifix and lights there, and was a bitter enemy of the Roman Catholics, he had little more patience with the Puritans. He was grasping, or at least