The top five most expensive printed books ever auctioned
The printing press is often cited as one of the most significant developments in the history of human civilisation - allowing for the wide scale dissemination of ideas across countries and continents.
Despite the ease with which books could be produced there are a number of early printed texts that, due to their historic significance and rarity, have sold for extraordinary sums at auction.
In ascending order, here are the five most valuable printed books ever auctioned:
Gutenberg Bible (honourable mention)
The first book to be printed with a movable type printing press, the Gutenberg bible is one of the most important books in the history of mankind.
Printed by Johannes Gutenberg in 1455, the book ushered in the beginning of a new age - including the development of the newspaper which allowed people to contextualise their worldview.
The printing press led to increased literacy, enlightenment and democratisation of knowledge - an effect often referred to as the Gutenberg Revolution.
Only 48 examples are known to have survived to the present day, of which just 21 are complete. One example sold to a Japanese bidder for $5.4m at Christie's New York in 1987 - a record price for a printed book at the time.
5. Shakespeare's First Folio
It is difficult to overstate Shakespeare's importance in the history of world literature. His eloquence, storytelling and characterisation have stood as the benchmark of Western cultural output for over 500 years - and even today his writing retains its vitality and relevance.
Despite the high regard with which he was held during his lifetime, he did not leave a comprehensive collection of his plays.
His contemporaries, John Heminges and Henry Condell, sought to rectify this and in 1623 they published the First Folio: Comedies, Histories & Tragedies by William Shakespeare, which contains 36 of his works.
Only 750 copies were ever produced, of which just 40 complete examples are known to exist. The record price was set in 2001, when a copy was bought by Microsoft co-founder Paul Allen for $6.1m.
4. Chaucer's Canterbury Tales
Written by Geoffrey Chaucer at the end of the 14th century, the Canterbury Tales are presented as a story telling competition by a group of pilgrims travelling to Canterbury Cathedral.
The work was an early example of a piece of English literature. In the past, books had predominantly been written in the court languages of French and Latin. The book's depiction of ordinary people, ranging from cooks to knights, offers a window into mediaeval life, alongside a satirical treatment of the issues of the day, including the class structure.
Just 12 copies of the 1477 first edition, the first book to be printed in England, are known to exist. In 1998, a copy sold for £4.6m ($7.2m) at Christie's London.
3. George Washington's Acts of Congress
George Washington's personal copy of the Acts of Congress, featuring his own annotations, takes the third spot after starring in its own dedicated auction at Christie's New York in 2012.
The book codifies the US constitution, bill of rights and other acts passed in the first congress of 1789.
It is finely bound, and embossed with gold, featuring Washington's signature on the title page along with the president's own family coat of arms.
The book sold for $9.8m - shattering an estimate of $2m-3m.
2. John James Audobon's The Birds of America
The Birds of America by John James Audubon was first issued as sets of plates, which were sold on a subscription to wealthy patrons. Audubon was determined to paint every bird in North America, and between 1827 and 1838 he produced 435 plates - issued as 87 sets of five.
The work was eventually published as a single folio - nicknamed "the Double Elephant Folio" because of its enormous size and weight.
Around 170 examples remain in existence, with the record set at £7.3m ($11.5m) at Sotheby's in 2010.
1. Bay Psalm Book
And finally, the most valuable book ever printed. The Bay Psalm Book is a small non-descript specimen - however looks can be deceiving. Its great value lies in its historical significance as the first book ever printed in North America.
A copy sold in November 2013 for $14.2m at Sotheby's New York - a new world record for a printed book.
First printed in 1640, just 20 years after the first pilgrims landed on Plymouth Rock, the book was issued in an edition of around 1,700 - of which just 11 are known to have survived.
It was purchased by David Rubenstein, the noted American financier and philanthropist, who plans to exhibit the book in libraries across the nation.
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