London Transport (LT) was the public name and brand used by a series of public transport authorities in London, England, from 1933. Its most recognisable feature was the bar-and-circle 'roundel' logo. With its origins in the Underground Electric Railways Company of London (UERL), the brand was first used by the London Passenger Transport Board (LPTB) to unify the identity of the previously separately owned and managed London Underground, Metropolitan Railway, bus and tram services. The London Transport brand was extended under the direction of Frank Pick to all aspects of transport operation including poster designs, tickets, train livery, seat upholstery and the station architecture of Charles Holden. The brand was discontinued in 2000 and replaced with that of Transport for London, which has built on the legacy of London Transport and incorporated many of its design features into its own house style.