From the MEWS archive is this model of a GWR King class seen at a Sandown Park exhibition. It is the last in the series of 30 Kings built In the late 1920s and early 30s and was originally named King Henry II.

GWR chief mechanical engineer Charles Collett developed this powerful locomotive to pull 13 plus carriage express trains. Aided by Hawkesworth, Collett designed the King Class to the maximum dimensions of the original GWR 7 ft 1⁄4 in broad-gauge engineering used to develop its mainline resulting in the largest loading gauge of all the pre-nationalization railways in the UK, with a maximum height allowance of 13 feet 5 inches .This restricted where they could operate under both GWR and British Railways ownerships.

To accommodate the largest possible boiler, King class were fitted with 6ft 6in main driving wheels, smaller than the Castle class. This resulted in both the GWR's most powerful locomotive design, plus  higher tractive effort than the Castle. This combination allowed the King class to pull the higher-weight express trains from London to Bristol and onwards to the West Country, at a higher-speed timetable average than the Castle.

The class was to be originally named after cathedrals, but in light of the invitation to feature in the Baltimore and Ohio Railroad's centenary celebrations, the GWR decided to make them more notable by naming the class after British Kings. No.6000 King George V was officially preserved as part of the national collection. Two other Kings are preserved.