A rare three rotor German Enigma machine led an auction at Sotheby's London on July 11, achieving £93,750 ($135,394).

It dates to 1943 and remains in very good condition, with only minor restorations carried out.

The Nazis used Enigma machines to transmit messages across Europe

The Enigma machine was patented in 1918 and first found its application in industry and government.

Later it was adopted by the Nazis and used to secretly transmit instructions to their forces across Europe.

However, the code had actually been cracked some years before the war by a team of Polish mathematicians.

They shared their information with British intelligence, which set up a dedicated facility for decrypting the messages at Bletchley Park.

Sotheby's explains: "Few Enigma machines survived the War intact: the Germans destroyed them as they retreated, and for decades after the war governments around the world kept close control over Enigma technology (indeed two of Turing's wartime papers on cryptography remained classified until 2012).

"So secure was the system believed to be that some governments, unaware of the work of Bletchley Park, continued to use Enigmas after 1945."

The record for an Enigma machine is $269,000, set for a very rare four-rotor specimen at Bonhams last year.

Take a look at all our militaria for sale here.

The eclectic auction included a wealth of other items, like a first edition copy of Charles Darwin's On the Origin of Species.

It sold for £68,750 ($99,289).

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