A portrait of Julian the Apostate and his wife Helena – or is it?

There’s an image which circulates online, purporting to be a depiction of Julian the Apostate and his empress, Helena.  Here it is:

The item is from Wikipedia (where else?), and adorns the page dedicated to Helena.  From there it has spread to many sites, book covers, etc.

But is it genuine?  Indeed what is it?  Where is it held?

The Wikimedia page (where I have corrected the description) tells us that it was uploaded in 2011, and gives http://www.cachecoins.org/juliancarving.jpg as a source.  That website still exists, but the url is dead.  Nor does a Google Images search reveal much.

Luckily for me, I searched using Google Lens, on my Android phone.  This led me to a fascinating article by Prof. Sir John Boardman, “A pursuit of art in miniature: The Fourth Duke of Marlborough’s collection of gems”, in: Apollo – The International Magazine for Collectors (2008), 57-61, online at the Beazley Archive in Oxford here.  On page 60, we find a real colour photograph, given as figure 16:

With the legend:

16. Two Divine or Imperial Heads, electrotype copy of Figure 15, showing its now lost 16th-century silver-gilt mount. Beazley Archive, University of Oxford.

The text tells us that this is a reproduction, a cast, made using the electrotype process, of a genuinely ancient item, a gem, specifically a cameo, which was once in the collection of the Duke of Marlborough and is now in the British Museum.  Figure 15 gives a photograph, with the legend:

15. Two Divine or Imperial Heads, sardonyx cameo, 1st century AD. 22 x 15 cm. British Museum, London.

Dr. B. explains:

The gems are often the better for their elaborate mounts, renaissance or later in date. Not all museums have retained them unless they are as interested in jewellery as in engraving. … The mounts themselves can sometimes be as historically important as their contents. The great cameo in the British Museum (Fig. 15) with two divine or imperial heads boasted a metal mount of some complexity, of 16th-century date. I show it also in Story-Maskelyne’s electrotype (Fig. 16) because the original gilt silver had been replaced with a copy by the time it reached the museum, and it had lost the two inscriptions in the wreaths. A metal back had been added in the 18th century recording its possession by a mysterious ‘Marquis de Fuentes’ – this also survives only in a cast.

Few will know what electrotype casts were.  This is a way of getting a metal cast of an object, invented in the 19th century.  Here’s how it works.

You take an impression of the object using soft material, such as clay, and then suspend the impression in a solution of a copper electrolyte.  Passing a current through the solution causes copper to be deposited on the clay mould, thereby creating a copper copy of the original.  The process was used for printing drawings engraved on metal well into the twentieth century.

The electrotype cast exists because the 7th Duke of Marlborough arranged for Prof. Nevile Story-Maskelyne to catalogue his collection of ancient gems.  Dr S.-M. made electrotype casts of all the cameos, and these now reside in the Beazley Archive at the university of Oxford.  No doubt the image used in the Apollo article comes from there.

Our image, then, is not a real colour photograph at all. It looks like a black-and-white image, perhaps from a book, which has been given a fake colour.  The colourist was unaware of the real colours of the object.

We learn from Dr Boardman that the original cameo itself today is in the British Museum.  And so it is, inventory number 1899,0722.1, and – how wonderful is the British Museum – it is online with full description here.  The description reads:

Three-layered sardonyx cameo engraved with confronted portrait-busts of two members of the imperial family as Jupiter Ammon and Juno-Isis; the female resembles the princesses of the imperial house of Gaius (Caligula) or Claudius. 37-50 (circa) .

Wikipedia has this splendid photograph of it here:

That is a really lovely object.  It can be seen in room G70, apparently, so do look out for it if you can visit.  But there is no connection to Julian the Apostate.