Alistair Lexden provided an introduction to his film about Bonar Law (Conservative Party leader, 1911-21 and 1922-23; Prime Minister, 1922-23) in an article published in November last year.
The film itself is now available on the BBC Parliament Channel. Follow the link to watch it: https://www.bbc.co.uk/iplayer/episode/m000rm84/prime-properties-bonar-law