The 30 'King' class 4-6-0s were the GWR's most prestigious express passenger engines. When introduced in 1927 they were the most powerful steam locomotives in Britain. The most famous was No. 6000 King George V which visited the USA for the Baltimore & Ohio Railroad centenary. It was preserved on withdrawal in 1962 and after steam had finished on British Railways it 'broke the ban' when it returned to main-line operation, setting the scene for today's numerous steam specials. Three 'Kings' survive and are always a huge draw for enthusiasts whenever they appear on the main line, on heritage railways or exhibition display.