In the 16th century there was some violent resistance to the replacement of Catholicism with Protestantism in the Prayer Book Rebellion. In 1548 the college at Glasney, a centre of learning and study established by the Bishop of Exeter, had been closed and looted (many manuscripts and documents were destroyed) which aroused resentment among the Cornish. They, among other things, objected to the English language Book of Common Prayer, protesting that the English language was still unknown to many at the time. The Prayer Book Rebellion was a cultural and social disaster for Cornwall; the reprisals taken by the forces of the Crown have been estimated to account for 10–11% of the civilian population of Cornwall. Culturally speaking, it saw the beginning of the slow decline of the Cornish language.