Rare first edition books co-authored by Charles Darwin are expected to sell for �15,000-�20,000 at an auction in Aylsham this week.

The Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836 was Darwin's first published work, according to Andrew Bullock, head of Keys auctioneer's book department.

Darwin went on to revolutionise the world of science with the 1859 publication of his groundbreaking work On the Origin of Species.

The auction, on Thursday March 29, will see three of the Narrative volumes and an appendix, dated 1839, go under the hammer, all in the publisher's original cloth binding. The third volume incudes Darwin's observations on the expedition, according to Mr Bullock.

The sale also includes a first edition of the first published book on birds to contain coloured illustrations.

A Natural History of Birds, written by Eleazar Albin 'and carefully colour'd by his daughter and self..' was published in 1731. The two volumes are expected to fetch between �6,000 and �8,000.

And a first edition of Dennis Wheatley's first novel The Forbidden Territory, published in 1933 and in its original dust jacket, will also be in the sale. Experts estimate it will realise �2,000-�2,500.

As previously reported, the following day will see Winston Churchill's custom-made earplugs go under Keys' hammer, complete with the original casts of the wartime hero prime minister's ears. The lot is expected to sell for about �2,000.