When London Transport was formed in 1933 it became the world's largest municipal transport undertaking, peaking at some 9,000 buses, trams and trolleybuses. London Transport inherited a small selection of historic vehicles that had been retained for preservation and continued this process of retention and display, leading eventually to the establishment of the London Transport Museum. With the growth of private preservation from the 1950s, it is no surprise that there are now more ex-London Transport vehicles preserved than from any other company and that these can be regularly seen both static and active at heritage and museum sites and at many enthusiast-themed events.