The first Library of Parliament Act was given Royal assent April 14, 1871. The direction and control of the Library was to be vested in the Speakers of both Houses, assisted by a joint committee. At this time provisions were made for a staff to consist of one librarian, one assistant librarian, two clerks and two messengers.
On May 6, 1885, a resolution was passed in the House of Commons that “the officers and servants of the Library of Parliament should consist of: two officers, one to be called the General Librarian, the other the Parliamentary Librarian, and to hold a joint commission as “Librarians of Parliament” and to have equal powers…”
This was amended in 1955. The Parliamentary Librarian was given “the control and management of the Library” while the position of General Librarian was changed to that of Associate Parliamentary Librarian who would "perform the duties and functions of Parliamentary Librarian during his absence, illness or other incapacity or during a vacancy in the office of Parliamentary Librarian."