Trolleybuses first came to London in a small way, being introduced in 1931 by London United Tramways. When the Second World War brought development to a halt, London Transport had an operational fleet of 1,671 trolleybuses - by far the largest fleet in the world.

Ken Blacker wrote the very first Capital Transport book 'Trolleybus' in 1975 and has now produced this very detailed definitive second volume of the history of the system.