how much of the Prayer Book is Cranmer's personal composition. Generations of liturgical scholars have been able to track down the sources that he used, including the Sarum Rite, writings from Hermann von Wied, and several Lutheran sources including Osiander and Justus Jonas. It is more problematic to determine how Cranmer worked on the book and with whom he worked. Where information about his possible helpers is lacking, he is given the credit for the editorship and the overall structure of the book. The use of the new Prayer Book was made compulsory on 9 June 1549. This triggered a series of protests in Devon and Cornwall where the English language was not yet in common usage, now known as the Prayer Book Rebellion. By early July, the uprising had spread to other parts in the east of England. The rebels made a number of demands including the restoration of the Six Articles, the use of Latin for the mass with only the consecrated bread given to the laity, the restoration of prayers for souls in purgatory, and the rebuilding of abbeys. Cranmer wrote a strong response to these demands to the King in which he denounced the wickedness of the rebellion. On 21 July, Cranmer commandeered St Paul's Cathedral where he vigorously defended the official Church line. A draft of his sermon, the only extant written sample of his preaching from his entire career, shows that he collaborated with Peter Martyr on dealing with the rebellion. Consolidating gains (1549–1551) The Prayer Book Rebellion and other events had a negative effect on the Seymour regency. The Privy Council became divided when a set of dissident Councillors banded together behind John Dudley in order to oust Seymour. Cranmer and two other Councillors, William Paget, and Thomas Smith initially rallied behind Seymour. After a flurry of letters passed between the two sides, a bloodless coup d'état resulted in the end of Seymour's Protectorship on 13 October 1549. Despite the support of religiously conservative politicians behind Dudley's coup, the reformers managed to maintain control of the new government and the English Reformation continued to consolidate gains. Seymour was initially imprisoned in the Tower, but he was shortly released on 6 February 1550 and returned to the council. The archbishop was able to transfer his former chaplain, Nicholas Ridley from the minor see of Rochester to the diocese of London, while John Ponet took