The vast British Pathe newsreel archive includes plenty of film of the London Underground: from grand openings to disasters, the Queen to cleaners, Piccadilly Circus in 1925 to Aldwych in the Second World War. They've put together a selection to mark the 150th anniversary.
I particularly liked this behind-the-scenes look at training in 'Underground School' during the 1950s. Who wouldn't want to play with that train set?