Throughout the history of Parliament, qualification for the
House of Lords remained largely unchanged. Seats were 
open only to hereditary peers, or to Bishops of the 
Church of England. Membership has grown steadily over 
the years - from around 70, at certain times in the 17th 
century, to approximately 1200 at present - but the most 
significant change in the House's character took place in 
1958, with the introduction of life peerage titles which 
cannot be passed on to their children.

Life peerages are awarded to individuals who have enjoyed
prominent careers in the arts or sciences, professions or trade unions, or at the end of a distinguished career in the Commons. The system significantly changed the character of the House, not only because it introduced expertise in specialised subjects, but also because it brought women into the Lords for the first time.