Mauritius "Post Office"
The "Post Office" postage stamps of Mauritius are among the rarest stamps in the world, and are of legendary status in the world of philately. Two stamps were issued, an orange-red one penny (1d) and a deep blue two pence (2d). .
- Country of Production = Mauritius
- Location of Production= Mauritius
- Date of Production= 21 September 1847
- Nature of Rarity = First stamps of the British Empire produced outside of Great Britain
- Number in Existence = 27 (as of 1981) 
- Face Value = Orange red: one penny Deep blue: two pence
- Estimated Value = $4 million both on cover (1993)
The Mauritius were engraved by Joseph Osmond Barnard, born in England on August 10, 1816, who stowed away on a ship to Mauritius in 1838 . The designs were based on the then current issue of Great Britain stamps (first released in 1841), bearing the profile head of Queen Victoria and issued in two denominations in similar colors: one penny red brown and two pence blue. Although these locally-produced stamps have a distinct primitive character, they made Barnard’s “name immortal in the postal history of Mauritius” .
Five hundred of each value were printed from a single plate bearing both values and issued on September 21, 1847, many of which were used on invitations sent out by the wife of the Governor of Mauritius for a ball she was holding that weekend . The stamps were printed using the intaglio method (recessed printing), and bear the engraver's initials "JB" at the lower right margin of the bust. 
The words "Post Office" appear in the left panel, but on the following issue in 1848, these words were replaced by "Post Paid." A legend arose later that the words "Post Office" had been an error.
The stamps, as well as the subsequent issues, are highly prized by collectors because of their rarity, their early dates and their primitive character as local products. Surviving stamps are mainly in the hands of private collectors but some are on public display in the British Library in London, including the envelope of an original invitation to the Governor's ball complete with stamp. Another place where they can be seen is at the Blue Penny Museum in Mauritius. The two stamps also can be seen at the Museum for Communication (Museum für Kommunikation) in Berlin and in the Postal Museum of Sweden in Stockholm.
The "Post Office" versus "Post Paid" myth
In 1928, Georges Brunel published Les Timbres-Poste de l'Île Maurice in which he asserted that the use of the words "Post Office" on the 1847 issue had been an error . Over the years, the story was embellished. One version was that the man who produced the stamps, Joseph Barnard, was a half-blind watchmaker and an old man who absent-mindedly forgot what he was supposed to print on the stamps. On his way from his shop to visit the postmaster, a Mr. Brownrigg, he passed a post office with a sign hanging above it. This provided the necessary jog to his memory and he returned to his work and finished engraving the plates for the stamps, substituting "Post Office" for "Post Paid" .
These stories are purely fictional; philatelic scholars have confirmed that the "Post Office" inscription was intentional. . Adolphe and d'Unienville wrote that "It is much more likely that Barnard used 'Post Office' because this was, and still is, the legal denomination of the government department concerned". The plates were approved and the stamps issued without any fuss at the time. Joseph Barnard was an Englishman of Jewish descent from Portsmouth who had arrived in Mauritius in 1838 as a stowaway, thrown off a commercial vessel bound for Sydney. He was not a watch-maker, although he may have turned his hand to watch repairs; not half-blind; and certainly not old; he was born in 1816 and was therefore 31 years old when he engraved the stamps in 1847 . In addition, several rubber stamps used in Mauritius on letters prior to these stamps also used the words "Post Office" , as did the first two stamps issued by the United States in July 1847 .
The Mauritius "Post Office" stamps were unknown to the philatelic world until 1864 when Mme. Borchard, the wife of a Bordeaux merchant, found copies of the one and two pence stamps in her husband's correspondence. She traded them to another collector. Through a series of sales, the stamps ultimately were acquired by the famous collector Ferrary, and were sold in auction in 1921.
Over the years, the stamps became legendary in the philatelic world and sold for increasing and ultimately astronomical prices. Mauritius "Post Office" stamps and covers have been prize items in collections of famous stamp collectors, including Arthur Hind, Alfred F. Lichtenstein, and Alfred H. Caspary, among other philatelic luminaries.  The greatest of all Mauritius collections, that of Hiroyuki Kanai, included unused copies of both the One Penny and Two Pence "Post Office" stamps, the "Bordeaux" cover with both the one penny and two pence stamps which has been called "la pièce de résistance de toute la philatélie"  or "the greatest item in all philately", and numerous reconstructed sheets of the subsequent issues.  Kanai’s collection was sold by the auctioneer David Feldman in 1993, the Bordeaux cover going for the equivalent of about $4 million. 
The subsequent issues are discussed in Postage stamps and postal history of Mauritius.
Reprints and forgeries
A number of full length studies have been published of the “Post Office” issue and the early stamps of Mauritius. These include:
- Hiroyuki Kanai, Classic Mauritius, Stanley Gibbons, London (1981) ISBN 0852592515 -- an illustrated work on the author's famous Mauritius collection, including photos of reconstructed plates, postmarks and postal history.
- David Feldman SA, Mauritius: Classic Postage Stamps and Postal History, Switzerland (1993), illustrated auction catalog including the Kanai collection (see above), with Supplement providing detailed information on plating positions of the "Post Paid" and the "Lapirot" issues in their different states.
- Helen Morgan, Blue Mauritius: The Hunt for the World's Most Valuable Stamps, Atlantic Books (2006) ISBN 1843544350 -- a detailed study of the Penny Blues, including the social and economic factors that brought about the modern postal system in Mauritius and the resulting philatelic interest. The author compiled her sources and bibliography on a website: Blue Mauritius Research Companion.
- Scott Cat. nos. 1-2; Stanley Gibbons Cat. 3-25 (various states of wear)
- Kanai, Classic Mauritius, p. 17.
- Kanai, Classic Mauritius p. 21.
- Kanai, Classic Mauritius, pp. 20-21.
- Scott Cat. nos. 3-4.
- Kanai, Classic Mauritius, p. 20.
- Kanai, Classic Mauritius, pp. 15-18.
- L.M. Williams, Fundamentals of Philately, American Philatelic Society (rev. ed. 1990), p. 523; Kanai, Classic Mauritius, p. 24.
- Kanai, Classic Mauritius, p. 19.
- Georges Brunel, "Les Timbres-Poste de l'Ile Maurice: Emissions de 1847 à 1898", Editions Philatelia, Paris (1928)
- Kanai, Classic Mauritius, p. 19.
- Kanai, Classic Mauritius, p. 19-20; Peter Ibbotson, The Barnard Myth; Harold Adolphe and Raymond d'Unienville, The Life and Death of Joseph Osmond Barnard, The London Philatelist, vol. 83, pp 263-265 (December 1974).
- Kanai, Classic Mauritius, p. 19.
- Scott nos. 1 & 2.
- David Feldman SA, Mautitius: Classic Postage Stamps and Postal History Switzerland (1993) pp. 10-17.
- Roger Calves, quoted in David Feldman SA, Mauritius: Classic Postage Stamps and Postal History Switzerland (1993) p. 92.
- Kanai, Classic Mauritius.
- David Feldman SA, Mauritius: Classic Postage Stamps and Postal History, Switzerland (1993), Prices Realized supplement.
- Kanai, Classic Mauritius, pp. 22-23; Mauritius Reprint from Original Plate
- Fernand Serrane, The Serrane Guide (1998), pp. 234-235.