Black Book of the Exchequer

The Black Book of the Exchequer (Latin: Liber Niger Scaccarii) or Little Black Book (Liber Niger Parvus) is a collection of documents compiled for the English Exchequer early in the reign of King John (1199–1216) and now preserved in manuscript in the Public Record Office. It is usually attributed to Alexander of Swerford, who later compiled the Red Book of the Exchequer, including much of the same material.

Source: Wikipedia — Black Book of the Exchequer (CC BY-SA 4.0)