This document presents and discusses some newly-discovered evidence about the history of the House of Commons library in the 1840's and 1850's. It contains the minutes of the Standing Library Committee for the period 1840-56, and the plan of the librarian's house in 1850. In particular, it shows how Sir Robert Peel, in one of the last parliamentary acts of his life, overturned proposals from his old political rival, Sir Harry Inglis, and established a liberal and non-prescriptive collection policy for the institution, which lasted over 90 years.