A portrait of a mistress to King Charles II who held the title Baroness Petersfield sold for £13,000 at a recent auction.

The oil painting ‘attributed’ to French portraitist Henri Gascars, of Louise Renée de Penancoët de Kéroualle, (September 5, 1649, to November 14, 1734) went under the hammer at the Bellmans Auctioneers on October 12, at Wisborough Green.

As well as Baroness Petersfield, Louise was also the Duchess of Portsmouth and Countess of Fareham, with a pension and allowances – in 1681 alone, she received £136,000.

That is thought to be worth in the region of £35m in today’s prices.

Louise, born into a noble family at Château de Kéroualle, near Brest, was rumoured to have been deliberately chosen to fascinate Charles II.

When he did show favour, the French ambassador Colbert de Croissy and secretary of state Henry Bennet, 1st Earl of Arlington, supported her becoming his mistress, despite her being known as the ‘French spy.’

Although disliked by Charles’ other mistress Nell Gwynne, Louise retained her hold on him, ensuring he was received into the Catholic Church on his deathbed.