This article relies largely or entirely on a single source. (July 2018)
The Apostolic Camera (Latin: [Reverenda] Camera Apostolica), formerly known as the is an office in the Roman Curia. It was the central board of finance in the Papal administrative system and at one time was of great importance in the government of the States of the Church, and in the administration of justice, led by the Camerlengo of the Holy Roman Church.
Since the middle of the 12th century the Papal chamberlain (camerarius domini papae) was a regular member of the Curia, entrusted with the financial management of the papal court. At that early period the income of the papal treasury came chiefly from many kinds of census, dues, and tributes paid in from the territory subject to the Pope, and from churches and monasteries immediately dependent on him. Cencius Camerarius (later Pope Honorius III, 1216-27) made in 1192 a new inventory of all these sources of papal revenue, known as the Liber Censuum. The previous list dated back to Gelasius I (492-496) and Gregory I (590-604), and was based on lists of the incomes accruing from the patrimonies, or landed property of the Roman Church.
In the 13th century the Apostolic Camera entered on a new phase of development. The collection of the crusade taxes, regularly assessed after the time of Innocent III (1198-1216), imposed new duties on the papal treasury, to which were committed both the collection and distribution of these assessments. Moreover, during the course of this century the system of payment in kind was transformed into the monetary system, a process considerably influenced by the administration of the papal finances. The servitia communia of bishops and abbots (see Annates) were regulated at fixed sums. The income regularly yielded by them to the Curia is by no means small. To these were to be added the annates, taken in the narrower sense, especially the great universal reservations made since the time of Clement V and John XXII, the extraordinary subsidies, moreover, levied since the end of the thirteenth century, the census, and other assessments. The duties of the Apostolic Camera were thus constantly enlarged. For the collection of all these moneys it employed henceforth a great number of agents known as collectores.
With time the importance of this central department of finance became more marked. The highest administrative officers were always the chamberlain (camerarius) and the treasurer (thesaurarius) -- the former regularly a bishop, the latter often of the same rank. Next in order came the clerics of the Camera (clerici cameræ), originally three or four, afterwards as many as ten. Next to these was the judge (auditor) of the Camera. The two first-named formed with the clerics of the Camera its highest administrative council; they controlled and looked closely to both revenues and expenses. In their service were a number of inferior officials, notaries, scribes, and messengers. The more absolute system of ruling the Church which developed after the beginning of the 16th century, as well as the gradual transformation in the financial administration, modified in many ways the duties of the Apostolic Camera. The Camerarius (camerlengo, chamberlain) became one of the highest officers in the government of the Papal States, until the beginning of the 19th century, when new methods of administration called for other officials.
In 1870 what remained of the Papal States was annexed to the Kingdom of Italy and ceased to exist, replaced by the diminutive Vatican City: the Apostolic Camera ceased almost entirely to exercise any practical influence on the papal administration, and the income of the papal treasury since chiefly derived from Peter's-pence and other donations contributed by the faithful, the Camera lost its practical importance as a board of finance, for the revenue known as Peter's-pence is managed by a special commission. The officials who since constituted the camera -- the cardinal-camerlengo, the vice-camerlengo, the auditor, the general treasurer (an office unoccupied since 1870) and seven cameral clerics -- hold in reality quasi-honorary offices.
The Apostolic Camera must be distinguished from the treasury or camera of the College of Cardinals, presided over by the cardinal-camerlengo (Camerarius Sacri Collegii Cardinalium). It had charge of the common revenues of the College of Cardinals, and appears among the curial institutions after the close of the 13th century. It has long ceased to exist.