[1] Only eighteen were made between 1950 and 1956, sold only to buyers whom Rolls-Royce considered worthy of the distinction: the British royal family and heads of state.

[2] The Phantom IV chassis differed from those of the shorter, production post-War models, the Silver Wraith and the Bentley Mark VI; apart from a larger size and an engine with increased capacity and power, they have an additional cross-member at the centre of the cruciform bracing and 10-stud road wheel mountings.

[4] The IV is the only Rolls-Royce motorcar to be fitted with a straight-8 engine, which was powerful but could also run long distances at a very low speed, an important feature for ceremonial and parade cars.

All examples of this exclusive series were bodied by independent coachbuilders,[5] and most of their bonnets surmounted by the kneeling version of the Spirit of Ecstasy, which had been unveiled in 1934 and used in various other models.

The following was published on 19 July 1938 in the British magazine The Motor: The company wish to deny the rumour that the Phantom III is to be discontinued and replaced with another model having an 8-cylinder or other engine.

[7] Likewise, in 1939 and before the starting of hostilities, another straight-eight powered experimental automobile tested during and after World War II was a special Bentley Mark V, chassis 11-B-V,[9] fitted with a bored-out 6.3 litre eight-cylinder engine.

[10] Although the official Experimental Department name for this car was Comet,[11] its scorching performance earned it the fond epithet Scalded Cat.

The board members had earlier considered making a replacement for the pre-war Phantom III, but they were wary that such a large and expensive car might not have a market in the weak post-war economy.

Design and production of the first chassis of the new model was not at the Crewe factory, but at the experimental Clan Foundry at Belper,[16][17] which had been the home of the motor car branch during the Second World War.

[17] Its delivery was accompanied by a public announcement stating the Phantom IV had been "designed to the special order of Their Royal Highnesses, the Princess Elizabeth and the Duke of Edinburgh".

The limousine became an official state car of the United Kingdom upon Princess Elizabeth's accession to the throne in 1952; as such, it was repainted in the sovereign's colour scheme of royal claret and black.

[15] The passengers were to be immune from a Mauser bullet fired at ten paces, so W. A. Robotham recommended a body from Mulliner's of Chiswick, which "had many satisfied customers among the more unpopular rulers of the world".

[24] Without intending it, the Government of Spain's triple order in October 1948, along with the later Princess Elizabeth and Duke's commission in November that year, helped to give a decisive impulse to the existence of this model, as suggested by Martin Bennett in his book Rolls-Royce & Bentley: The Crewe Years and the number 9 September 1990 of the British magazine Classic Cars.

Most are linked to a specific customer's name, such as the King Farouk, the Maharajas of Baroda and Mysore, as well as the Americans Briggs Cunningham and James Melton.

[27] In 1956 the model was discontinued, by that time appropriate bodies for state use had been built on Silver Wraiths, which worked well for the factory, making dedicated Phantom IV production no longer necessary.

[28] In 1952 the cost of the Phantom IV chassis was $10,000 (£3,500) and with a limousine body, $20,000 (£7,000), a huge price premium but perhaps still not enough to allow a profit on the small number built (eighteen made, seventeen sold).

5034 Design 7162 Rear: Grey cloth State Car, Royal Mews, London, 2022 Park Ward Pick-Up Truck No.