The Papacy in the Late Middle Ages
Papal Government
Chancery
The government as a whole was referred to as the curia. As with royal governments, what had been the papal household grew into distinct divisions, and four main departments gradually became discernible.
The Chancery was the largest administrative deparment in the curia. Its primary concern was correspondence. Here were drafted letters, proclamations, legal documents, judgments and bulls; also all routine administrative correspondence, including the official responses to petitions. Curial letters were issued by the pope (or one of his officials) rather than in response to petitions.
It was headed by a vice-chancellor, who was usually a cardinal. This is why the cardinals were so closely tied to the papal court--they were the holders of the chief offices of papal government.
The chancery also had offical custody of the records of the curia (the Vatican Library had not yet been created). As a bit of trivia, you might like to know that the Latin bullum means a ribbon or tape. When papal documents were official, they had ribbons affixed with wax, and that's the origin of the term "papal bull." It has nothing to do with the animal!