Augustus aureus - £400k

The aureus was made between 27 BC and 18 BC and depicts a portrait of Augustus transformed into an ageless Apollo-like classical sculpture on one side. On its reverse is an image of a heifer. Just 22 examples of the heifer-reverse aureus minted during the reign of Augustus are known, of which 15 are in museums. Of the seven in private collections, the one that sold is among the best and most sought after. Brisk bidding at the London auction in 2014 saw the price of the coin soar past its pre-sale estimate of £300,000 and eventually go for a hammer price of £400,000.