William Shakespeare first folio gets £435,250
Only 200 examples of the book, without which many of the Bard's finest works would have disappeared, now remain.
Published in 1623, seven years after the playwright's death, it was first sold for 20 shillings, the equivalent of £100 today.
The folio contains 36 plays, 18 of which had not been published before. They include: 'Macbeth', 'Twelfth Night', 'The Tempest', 'The Taming of the Shrew' and 'As You Like It'.
The book was bought by an unnamed buyer at a price comfortably exceeding the £400,000 forecast.
Rupert Neelands of Christies said: "The preservation of over half Shakespeare's works is owing solely to the publication of the First Folio, the undisputed keystone of any serious collection of English literature."
The present copy was sold to Sir Thomas Munro of Lindertis in 1837 and remained in the family until 1976 when it was sold at Christies for £12,000.
The book was in a sale of manuscripts and literature which also included the first draft of one of Sir Winston Churchill's famous wartime speeches which made £139,250 (estimate £100,000 - £150,000). Sir Winston's moral-boosting speech was delivered to MPs during the height of the Battle of Britain in August 1940.