Archives of the Holy See
Collections of documents pertaining to the acts of the Holy See; also the place where they are kept.
Compiled for administrative purposes, they furnish a mine of information for historians, and are the most important archives in the world.
They existed in the earliest days of the Church, but extensive remains of documents do not antedate the thirteenth century.
According to a fairly reliable estimate of the arranged documents, the principal sections of what are called the Secret Archives total in round numbers 35,000 volumes and 120,000 loose documents.
The management of these archives is entrusted to a cardinal with various workers under him.
There are in the Vatican other archives besides the secret archives.
New Catholic Dictionary