See Parliamentary Papers vol. 53 , 'Mails conveyance. Return to an Order of the Honorable The House of Commons, dated 7 February 1840;- for, Copy of any Charter granted to any Joint Stock Company formed for carrying Mails to the Colonies' (Reprinted 3 February 1843).
In 1837 James MacQueen (1778-1870) put a plan to the Government for a steam packet service between England and the Caribbean; this was quickly followed by more ambitious proposals embodied in a 'General Plan for a Mail Communication between Great Britain and the Eastern and Western parts of the World; also to Canton and Sydney westward by the Pacific'. On MacQueen's initiative the West India Committee, an association in London of merchants and planters, gave its support to the formation of a company. Under the chairmanship of John Irving (d.1845), a merchant banker, the first meeting of the Directors of the Company was held in 1839. James MacQueen was appointed 'General Superintendent of Affairs'. In the autumn of 1839 the new company was granted a royal charter and the first mail contract was signed with the Admiralty in 1840. It provided for a service of steamships, twice in each calendar month, from a Channel port (eventually fixed as Southampton) to islands and ports in the West Indies. Connecting with this main line of steamers at the various points there was to be a feeder service of seven steamers and three sailing vessels, serving all the principal islands and countries of the Spanish Main, with an extension northwards to New York, Halifax and Nova Scotia. An annual subsidy of £24,000 was written into the agreement. Because the contract was with the Admiralty (the first contract with the Postmaster-General was made in 1864) the Royal Navy exercised a great deal of influence over the running of the ships. In an unprecedented building operation, fourteen large steam vessels and three small sailing ships were commissioned in time to start the service in December 1841. In 1846 the service was extended to link up with the west coast of South America (served by the Pacific Steam Navigation Company) over the Isthmus of Panama. A further extension followed in 1850, when a monthly service to Brazil and the River Plate was added to the extended West Indies contract. This new service was of great importance to the subsequent development of the Company. Royal Mail tried three times between 1852 and 1869 to get a foothold in the Australasian trade via Panama, but without any long-term success. A fourth attempt was made in 1906, in conjunction with the Orient Line (q.v.), but the partnership lasted only a year, after which the latter company obtained the mail contract for itself alone. There was a short-lived attempt to acquire berthing rights to Morocco, the Canaries and Madeira. This route was abandoned in 1919. The last five-year mail contract for the West Indies, signed in 1911, was not renewed owing to the advent of the First World War. However, the Canadian mail contract, for a fortnightly service between Canada, the West Indies and British Guiana remained in force from 1913 throughout the war; thereafter it was renewed by short-term extensions, until the increasing use of Canadian Government ships on the route brought it to an end in 1927. In addition, the company known as 'R.M.S.P. Meat Transports Limited' was formed in 1914 in order to put additional refrigerated tonnage on the Plate route. At the end of the First World War, the Company was allocated fourteen standard 'War' type freighters, as well as eleven ships of the Russian Volunteer fleet. From the beginning of the twentieth century the Royal Mail offered cruises on its vessels of which the most notable were Arcadian, Atlantis and Andes. From 1903 the policy of the Company under its Chairman, Owen Cosby Philipps (1863-1937), created Lord Kylsant in 1923, was to broaden the base of its operations by acquiring a controlling interest in a great number of shipping companies in diverse trades. Before the First World War, besides other less important enterprises, the Pacific Steam Navigation Company (1910), Lamport and Bolt and Elder Dempster (1911), the Union Castle Line (1912) and the Nelson Line (1913) became members of the group, with MacIver joining in.
Source: NMM archives: see ref. below.
Became the largest shipping group in the world in 1927 when it took over the White Star Line.
The company ran into financial trouble, and the British government investigated its affairs in 1930, resulting in the Royal Mail Case. Chairman Lord Kylsant was imprisoned in 1931 for misrepresenting the state of the company to shareholders. So much of Britain's shipping industry was involved in RMSPC that arrangements were made to guarantee the continuation of ship operations after it was liquidated. The Royal Mail Lines Ltd (RML) was created in 1932 and took over the ships of RMSPC and other companies of the former group.
Eventually absorbed into other companies and by the 1990s RML no more than the name of a Hamburg-Süd refrigerated cargo service from South America to Europe.
Archives are held at the National Maritime Museum: http://www.nmm.ac.uk/collections/archive/catalogue/record.cfm?ID=RMS
See also http://en.wikipedia.org/wiki/Royal_Mail_Steam_Packet_Company. Anya Addo, PhD student at Royal Holloway/NMM, is writing a thesis on the company: see http://www.nmm.ac.uk/blogs/collections/2010/08/the_royal_mail_steam_packet_co.html and http://www.nmm.ac.uk/blogs/collections/2009/06/the_royal_mail_steam_packet_co_1.html; for authorised share capital at foundation see http://www.merchantnavyofficers.com/rm1.html