The architectural development of the Palace has been intricately bound up with its role as the meeting place of the Lords and Commons since the 13th century. In 1341, the Lords and the Commons began to meet separately.
However, as the Palace was originally a royal residence, there were at first no purpose-built chambers for the two Houses.
House of Lords
The House of Lords originally met in the Queen's Chamber, a modest medieval hall at the south end of the complex. To cater for greater attendances, they moved again in 1801 to the Lesser Hall, once occupied by the Court of Requests.
House of Commons
The Commons in contrast did not initially have a recognised home of their own, although some of their debates were occasionally held in the Chapter House at Westminster Abbey.
In 1547, King Edward VI gave the Commons the permanent use of St Stephen's Chapel after the dismissal of the Canons of St Stephen's (members of a College which had held the services for the royal family) at the Reformation.
Parliament's permanent home
The Palace only became the permanent home of Parliament after 1512 when Henry VIII abandoned the palace in favour of the nearby Palace of Whitehall following a fire.
But even after the departure of the royal family, the site remained a royal palace with the official title of the Palace of Westminster. Over much of the subsequent centuries, control of the Palace and its precincts was exercised by the monarch's representative, the Lord Great Chamberlain.
Control of the Palace
By agreement of the Crown, control of the Palace passed from the Lord Great Chamberlain to the key representatives of the two Houses in 1965. The Lord Great Chamberlain, however, retains joint responsibility for the Chapel of St Mary Undercroft and Westminster Hall.