From the earliest days of its existence until the end of the 15th century, Parliament stored no archives of its own.
The medieval Clerks of the Parliaments and their staff were recruited from the Chancery. The files of petitions and Bills which accumulated during a session, together with the enrolment of proceedings and of Acts, were transferred by the Clerks from Parliament to the Chancery as government records. Today, these manuscripts are stored at the National Archives in Kew (formerly the Public Record Office).
The earliest document preserved in the Victoria Tower, the Archives' home today, dates from 1497. In that year, the Clerk of the Parliaments, Richard Hatton, while making up the Parliament Roll for that session and transferring it to the Chancery, decided to retain the complete series of sixteen 'original Acts' from which he had made the enrolment. This practice has been followed ever since.
Over the course of the 16th century, the Clerks began retaining other parliamentary record. This included the Journals of the House of Lords (from 1510), Petitions and Papers laid on the Table of the Lords (from 1531) and Bills (from 1558).
This continued until practically everything was kept at the Palace and only a duplicate Act was transmitted to the custody of the Public Record Office in the 19th century.