Prior to the Sandringham, numerous Sunderlands which had been built for the Royal Air Force (RAF) had been converted to a civilian configuration as early as 1942 to fulfil a requirement of the British Overseas Airways Corporation (BOAC) for additional long range airliners.

Around the conclusion to the conflict, Shorts was keen to produce a more refined and capable conversion of the Sunderland; the first prototype of which, which performed its maiden flight during November 1945, became known as the Sandringham I.

Being operated initially alongside the Hythes, the more comfortable conditions onboard the Sandringhams led to them being given greater priority for usage and routing alike.

At the height of the Second World War, it was recognised that the UK's flagship airline, the British Overseas Airways Corporation (BOAC), required new aircraft in its inventory.

[2][3] Following the end of the Second World War, BOAC opted to convert its Sunderlands to a less-austere standard, making them more suitable for peace-time operations; they became known as the Short Hythe.

[6] Specifically, the temporary and somewhat basic fairings implemented to cover turret positions could be replaced by more sophisticated low-drag counterparts to improve aerodynamic efficiency.

[8] During January 1946, a certificate of airworthiness was issued for the Sandringham I, it entered service with BOAC in June of that year after completing operational trials with RAF Transport Command.

[15] In 1946, BOAC recognised that its existing fleet of flying boats was insufficient to perform all of the routes it envisioned, thus the airline placed its first order for the Sandringham.

[16] During the following year, the Sandringham 5 was introduced into service with BOAC, which referred to it as the "Plymouth class" and operated it mainly the company's Far East routes from Southampton via Alexandria to Hong Kong and Tokyo.

The type quickly proved to be both reliable and popular with the travelling public, leading to BOAC ordering the improved Sandringham 6, which it called the Bermuda Class, in 1948.

[17] However, these operations were quickly overshadowed by other developments, with BOAC choosing to replace its flying boats on several routes with land-based Lockheed Constellation airliners during 1949.

This customer's small fleet was specially equipped with flying in cold prevailing conditions, although services had to be halted during the winter regardless; they also featured the same air-to-surface-vessel radar sets as fitted to the wartime Sunderland V for navigation purposes, helping the crew avoid mountainsides and safely operate from the fjords.

[18] In October 1954, Captain Sir Gordon Taylor flew his newly acquired Sandringham 7 from the UK to Australia to begin a series of flying boat cruises of the south Pacific.