Continual and sometimes heated interest is shown in the control by governments over documents in their possession, and in the time during which access to them is denied - and not only on the part of the historians to whom the documents are of prime concern. Professor Chadwick summarises the gradual establishment of the papal records down to the beginning of the nineteenth century, when they were carried off to Paris on the orders of Napolean. Their return (for the most part) to Rome and the subsequent history of the relationship between their guardians and would-be users provide a lively narrative of human as well as historical interest. The author shows how an argument developed within the Vatican itself between the statesmen who wished rigorously to restrict what was released to the public and the historians who wanted free access. This important study of how new attitudes and techniques of history affected the Church is based upon the author's Herbert Hensley Henson Lectures in Oxford 1976, and will interest documentalists and general readers as well as ecclesiastical and general historians.