Princes William and Harry Portrait, National Portrait Gallery

The latest official royal portrait, and the first painted portrait featuring the Princes William and Harry, hangs in a small room at the National Portrait Gallery among a selection of royal portraits of the Windsors. There’s the rather quirky one of the Queen Mother, painted in 1989 by Alison Watt, an artist who sought to capture her sitter “as ordinary as possible”. What our attention seems most drawn to is the china cup turned upside down on the arm of the Queen Mother’s armchair. Eh?

Then there is the immensely engaging portrait of Charles and the boys taken in 2004 by Mario Testino. Testino is a photographer who knows a thing or two about flattering his subjects - he is, undoubtedly, a genius at making sitters look sexier than they‘ve ever looked in their lives. Even Prince Charles. Absolutely. Mmm, that light tan, that invitingly open-necked white shirt. And his boys, now young men, open-necked too and full of virile swagger, but in a nicely understated, approachable way.  As I heard one visitor to the gallery put it, “Charles looks like an ageing Lothario in that one." With their shiny white grins, they could all be auditioning as Bee Gees lookalikes.

There’s very little sex or swagger, even in an understated way, in Nicola "Nicky" Philipps’s new double portrait of William and Harry. In fact, it’s the very opposite of the royal swagger portrait, even though they’re both kitted out in military regalia, with William wearing the star and sash of the Order of the Garter, and Harry his Afghanistan campaign medal. In its fluid, impressionistic style, we are reminded of the portraits of John Singer Sargent, but this has none of Sargent’s bravura flash and dazzle. The tone is low-key, serious, even a little sombre - these are young men who know the value of duty, who are respectful to Queen and country, and, above all, cognisant that men younger than they are currently dying in active service, in a war that Harry himself recently fought in. So this is a portrait that is very much on-message: their days, we are being told, as paparazzi-snapped, feckless turbo-Sloanes who frequently fell out of Boujis are definitely over. Thank the Lord.

Like their great-grandmother in Watt's nearby portrait (though with none of the endearingly odd-ball domestic accoutrements), there is also something touchingly ordinary about them. They appear relaxed - Harry sits, leaning slightly forward, with a hand resting on his hip, while William leans against a door post, their eyes locked in a moment of private exchange - though we know that having one’s portrait painted is anything but relaxing. Furthermore, Harry is literally looking up to his brother, signalling William’s higher status.

Philipps adheres to the traditions of royal potraiture, and the image resonates with the history of the genre. Yet this portrait has a thoroughly modern flavour. Capturing a quiet, fleeting and seemingly private moment, this is a far cry from the style of the grand portrait of previous royal households. Both intimate and reserved, it is also faintly dull, a little too dutifully conventional to be truly arresting. But such are the constraints of royal portraiture. It tells us something about the new-found maturity of these two young men that makes them fit to serve.

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