Bunyan began his work while in the Bedfordshire county prison for violations of the Conventicle Act of 1664, which prohibited the holding of religious services outside the auspices of the established Church of England. Early Bunyan scholars such as John Brown believed The Pilgrim's Progress was begun in Bunyan's second, shorter imprisonment for six months in 1675, but more recent scholars such as Roger Sharrock believe that it was begun during Bunyan's initial, more lengthy imprisonment from 1660 to 1672 right after he had written his spiritual autobiography Grace Abounding to the Chief of Sinners.