Gregorian Reform
The Liber Censuum Romanæ Ecclesiæ (Latin for "Census Book of the Roman Church"; also referred to as the Codex of Cencius) is an eighteen-volume (originally) financial record of the real estate revenues of the papacy from 492 to 1192. The span of the record includes the creation of the Apostolic Camera and the effects of the Gregorian Reform. The work constitutes the "latest and most authoritative of a series of attempts, starting in the eleventh century, to keep an accurate record of the financial claims of the Roman church". According to historian J. Rousset de Pina, the book was "the most effective instrument and [...] the most significant document of ecclesiastical centralization" in the central Middle Ages.