Princess Beatrice was the vision of elegance in a burgundy ensemble as she joined her husband and in-laws for dinner. 

The royal, 35, and Edoardo Mapelli Mozzi, 40, were all smiles as they left Arlington restaurant in Mayfair on Wednesday evening.

They appeared in good spirits after enjoying the evening with Nikki Williams-Ellis MBE - Edo's mother - and her husband David Williams-Ellis.

For last night's outing, the King's niece wore a deep purple coat with golden buttons over a sophisticated black top and maxi skirt.

The outfit was cinched at the waist with a belt, and Beatrice completed the look with some simple heels.

Princess Beatrice was the vision of elegance in a burgundy ensemble as she joined her husband and in-laws for dinner

She styled her caramel tresses in relaxed waves, and opted for a minimal make-up look.

Elsewhere, Edo opted for a simple white button-up, black blazer and khaki trousers. 

He carried an umbrella to shield himself from potential rain, holding hands with his wife as they exited the restaurant.

Meanwhile his glamorous mother donned a bohemian print dress and suede jacket for their dinner.

David - who is Nikki's third husband- has become the go-to sculptor for high society, with Tatler calling one of his pieces 'the ultimate marker of taste'.

The Northern Ireland born artist, who was educated at the Stowe School in Buckinghamshire, is also the great-nephew of Clough Williams-Ellis, the Welsh architect known chiefly as the creator of the Italianate village of Portmeirion in North Wales - famed as where The Prisoner was filmed.

Meanwhile, Nikki's first husband, Edo's father, is a member of Italian nobility and former British Olympic skier his dual Italian and British citizenship. 

His former wife, three-times married Nikki, mixes in English high society and gained an MBE for 'political service' when David Cameron announced his honours list after leaving Number 10 in 2016. 

The royal, 35, and Edoardo Mapelli Mozzi , 40, were all smiles as they left Arlington restaurant in Mayfair on Wednesday evening

They appeared in good spirits after enjoying the evening with Nikki Williams-Ellis MBE - Edo's mother - and her husband David Williams-Ellis

The couple divorced when their son and his sister Natalie were young, with Nikki now wed to David following the tragic death of her second husband Christopher Shale in 2011 at the age of 56.   

Christopher was a senior Tory and a close friend of former prime minister David Cameron. He collapsed and died in 2011 at Glastonbury Festival, after going missing for about 18 hours before he was found in a cubicle in the VIP area.

An inquest subsequently found he had been suffering from undiagnosed heart disease resulting from high blood pressure.

So devoted was Edo to his stepfather that he named his son Christopher, with ex partner Dara Huang, after him.

At the time, a distraught then- Prime Minister David Cameron said: 'A big rock in my life has suddenly been rolled away.' 

For last night's outing, the King's niece wore a deep purple coat with golden buttons over a sophisticated black top and maxi skirt

The outfit was cinched at the waist with a belt, and Beatrice completed the look with some simple heels

Taking to Instagram on the 10th anniversary of his stepfather's passing, Edo shared a collection of images - including one of his mother, Nikki, and Christopher on their wedding day, with Beatrice's mother Sarah Ferguson pictured alongside them. 

Edo wrote in the emotional post: 'Chrisdog, Pups, I can’t believe it has been 10 years. Not a day goes by without me thinking of you and leaning on all the lessons you taught me.

'You once said on my 18th birthday that being my stepfather was the greatest honour and privilege of your life. I echo this, being your stepson is the greatest honour of my life and I would never be standing here today without you.

'I know how proud you would be of us all today and so wish you had got to meet your three and soon-to-be four grandchildren. What joy they would have brought you.

'I was just Wolfie’s age when you came into my world and changed everything. You always believed in me, with unconditional love. You taught me honestly, laughter, hard work and empathy. I love you today and always,' he concluded.

Property developer Edo is the son of Alessandro Mapelli, a count and a former alpine skier, who competed for Team GB, and three-times-married Nikki.

Alessandro is an Italian count now 72 and known informally as Alex.

Nikki was married to Christopher Shale, a senior Tory and a close friend of former Prime Minister David Cameron, before his death at Glastonbury Festival (pictured, Edo with Nikki and David Cameron in 2011 after the memorial service) 

He skied for Great Britain at the 1972 Winter Olympics in Japan, and is a firm fixture in European high society. He was educated at Downside School in Somerset and is currently married to his third wife, Ebba; the couple live in a luxurious home in Provence.

Beatrice has long enjoyed a close relationship with her property developer husband's father.

The count is keen for the Italian lineage to continue, it seems. He previously told  MailOnline: 'Edoardo is the only male descendant taking the family into the next generation. He is a count — his wife will be a countess automatically and any of their children will be counts or nobile donna.'

Edo stands to inherit his father's glamorous palazzo, Villa Mapelli Mozzi, which is a stone's throw from Milan in Northern Italy.

Nikki has been a friend of the Yorks - particularly Sarah Ferguson - for decades and is considered well connected in high society - she once owned a successful property company.

Edo's mother split from Alessandro when her son was young, keeping custody of Edo and his sister Natalia, while her former husband moved to France to live.