Peter Phillips and his new NHS nurse girlfriend Harriet Sperling put on a cosy display as they walk hand-in-hand at Prince William's charity polo match

She's already been introduced to the King and Queen, and now Peter Phillips' new girlfriend Harriet Sperling has stepped out at an event attended by Prince William.

The couple put on cosy display as they walked hand-in-hand at the Out-Sourcing Inc Royal Charity Polo Cup at the Guards Polo Club at Windsor in aid of 11 different charities supported by both the Prince and Princess of Wales.

Princess Anne's son, 46, who is 18th in line to the throne, has been dating Harriet, 44, for just a short period of time after breaking up with his partner of three years Lindsay Wallace earlier this year.

The smitten pair have since spent their summer at an array of high society events - including Royal Ascot, Wimbledon and the Badminton Horse Trials.

Now, the couple have joined Peter's cousin William, 42, as he shows off his polo skills at the annual charity match.

She's already been introduced to the King and Queen, and now Peter Phillips' new girlfriend Harriet Sperling has stepped out at an event attended by Prince William

She's already been introduced to the King and Queen, and now Peter Phillips' new girlfriend Harriet Sperling has stepped out at an event attended by Prince William

NHS nurse Harriet put on an elegant display in a Beulah London V-neck floral dress as she walked alongside the King's nephew.

It is the 13th time William has played in the polo match and the total sum raised after today is expected to reach an incredible £13million.

The charities concerned are all close to the hearts of the couple and include emergency services, mental health, early years, conservation and the armed forces, and many are patronages.

Peter and Harriet's outing comes as Princess Anne returned to royal duties for the first time since suffering a concussion in a horse-related accident.

The Princess Royal was taken to Southmead Hospital in Bristol last month after she was reportedly kicked by a horse at her Gatcombe Park estate in Gloucestershire. 

The 73-year-old royal, a skilled horsewoman who competed in the 1976 Montreal Olympics, was going for a walk when the incident occurred. 

Emergency services were sent to the estate and, after being given medical care at the scene, Anne was transferred to hospital for tests, treatment and observation. 

Today, she was visiting the Riding for the Disabled Association (RDA) National Championships at Hartpury University and Hartpury College in Gloucestershire after recovering from her dramatic injury. 

The couple put on cosy display as they walked hand-in-hand at the Out-Sourcing Inc Royal Charity Polo Cup at the Guards Polo Club at Windsor in aid of 11 different charities supported by both the Prince and Princess of Wales

The couple put on cosy display as they walked hand-in-hand at the Out-Sourcing Inc Royal Charity Polo Cup at the Guards Polo Club at Windsor in aid of 11 different charities supported by both the Prince and Princess of Wales

The smitten pair have since spent their summer at an array of high society events - including Royal Ascot, Wimbledon and the Badminton Horse Trials

The smitten pair have since spent their summer at an array of high society events - including Royal Ascot, Wimbledon and the Badminton Horse Trials

The royal appeared in high spirits as she attended the event, smiling as she met members of the charity, which she has been a patron of since November 1971.

Meanwhile, Peter was recently spotted packing on the PDA with his new girlfriend Harriet - as the pair attended day four of the Royal Ascot last month.

The loved up couple was pictured kissing as they attended the equestrian event in Berkshire.

In May, the couple spent the weekend together at the Badminton Horse Trials, where they were spotted strolling hand-in-hand.

And the pair didn't hold back on affections this afternoon either as they were snapped leaning into one another and sharing sweet glances.

After an affectionate peck with her boyfriend, Harriet was spotted enjoying an animated chat with Queen Camilla.

And it seems Peter's family are keen on his new romance, as his cousin Princess Beatrice was also snapped giving her a warm hug and kiss on greeting.