Kylie Jenner’s penchant for her famously full pout might seem like a very modern phenomenon.

She is regularly seen on Instagram showing off her luscious lips to the world.

But conservators at English Heritage have discovered that the reality star’s facial features are by no means anything new.

Experts who were restoring a painting of Jacobean beauty Diana Cecil found that her lips had been made fuller and her hair given more depth by a mystery restorer years later.

Cecil, who was one of the great beauties of the early 17th century, was the great-granddaughter of William Cecil, one of Queen Elizabeth I’s closest advisors.

Experts who were restoring a painting of Jacobean beauty Diana Cecil found that her lips had been made fuller and her hair given more depth by a mystery restorer

Kylie Jenner ‘s penchant for her famously full pout might seem like a very modern phenomenon. She is regularly seen on Instagram showing off her luscious lips to the world

Her newly-restored portrait is going on display next week at neo-classical  Kenwood House in North London

The painting was damaged significantly when it was rolled widthways, which may have resulted in the need for a touch-up.

But the experts were left baffled by the overpainting of Cecil’s lips and hair.

Conservators have also removed layers of yellowing varnish to reveal Cecil’s natural colour. She was aged 31 when the depiction was produced.

During the restoration, the date of the portrait along with the signature of the artist – Cornelius Johnson – was found in the corner.

It was originally thought to have been painted in 1638 but the actual date was 1634.

Cecil’s choice of attire – including a silk dress, the red ribbon across the front of her bodice and the red rose on her breast – was the height of fashion at the time.

English Heritage’s paintings expert Alice Tate-Harte finishes conserving a painting of 17th-century noblewoman, Diana Cecil

The painting is going back on display at Kenwood House in North London from next week

Alice Tate-Harte, collections conservator at English Heritage, said: ‘As a paintings conservator I am often amazed by the vivid and rich colours that reveal themselves as I remove old, yellowing varnish from portraits, but finding out Diana’s features had been changed so much was certainly a surprise!

‘While the original reason for overpainting could have been to cover damage from the portrait being rolled, the restorer certainly added their own preferences to “sweeten” her face.

‘I hope I’ve done Diana justice by removing those additions and presenting her natural face to the world.’

The 1634 portrait is one of two of Cecil that are displayed at Kenwood. The other was painted by artist William Larkin when she was 15.

Both paintings are part of the Suffolk Collection, which was gathered over the course of 400 years by the Earls of Sussex and Berkshire.

The painting is part of the Suffolk Collection, which was gathered over the course of 400 years by the Earls of Sussex and Berkshire

During the restoration, the date of the portrait along with the signature of the artist – Cornelius Johnson – was found in the corner. It was originally thought to have been painted in 1638 but the actual date was 1634

It was give to the nation in 1974 in the will of Margaret ‘Daisy’ Howard, the 19th Countess of Suffolk.

Cecil was from a powerful noble family. Her first husband was Henry de Vere, 18th Earl of Oxford.

He died siege of Breda just a year after their 1624 wedding.

Cecil went on to marry Lord Thomas Bruce, who later became the 1st Earl of Elgin.

Cecil’s sister Elizabeth married Thomas Howard, the 1st Earl of Berkshire.