Princess Anne is seen studying her notes as she heads to a meeting staff at Save The Children's headquarters

Princess Anne proved she's earned her reputation as the hardest-working royal when she read a large book of notes on her way to a royal engagement on Wednesday morning.

The 73-year-old Princess Royal – who has been dubbed the 'right hand of the King' thanks to her reputation for her busy work schedule – was spotted on an outing in London.

Even behind the scenes she was busy as she prepared to meet staff at Save The Children's headquarters in Farringdon.

She has been a patron of Save the Children UK since 1970 – the first major charity associated with the King's sister – and last month celebrated 50 years of work in Sri Lanka during her royal tour.

The princess was spotted in a beautiful green coat as she headed out in her black Range Rover with the motorcade surrounding it.

As would be expected at royal engagements, she was flanked by police escorts on motorcycles as she passed through the streets of central London.

The outing marks yet another event in her busy schedule: she is the first royal woman to return to duty after the Christmas holidays.

It follows her busy schedule of commitments during her tour of Sri Lanka, during which she described herself as the 'eyes and ears' of the monarchy.

During the successful three-day visit with her husband Sir Timothy Laurence, she also carried some of her bags down the steps of the plane when they first arrived.

During an interview during the tour, she was asked about her workload and replied: “Well, I think in the context of the monarchy it takes more than one person to be able to keep in touch, and we are part of the eyes and ears .

“So as much as possible we just want to get out there and find out what's going on and help people who are doing incredible work wherever they are in the country and that applies here as well.

“Look here, there are charities here that have a good reputation, and they do fantastic work and that kind of ethos needs to be supported wherever you find it, so it's not difficult.”

With King Charles preparing for surgery and the Princess of Wales also out of action after major abdominal surgery, Anne is leading the way in attending royal engagements.

The Princess Royal, 73, has been dubbed the 'king's right hand' thanks to her reputation for her busy work schedule

Her motorcade – consisting of two range robbers and two police escorts on motorcycles – made its way through the streets of central London

Anne described herself as the 'eyes and ears' of the monarchy during her tour of Sri Lanka earlier this month (pictured)

The 75-year-old monarch is currently resting at the 20,000-acre Sandringham estate in Norfolk with Queen Camilla.

On Monday, the Queen told a member of the public during a visit to Swindon that Charles is doing 'fine' as he prepares for surgery this week.

The day before he had missed a church service near Sandringham, where he was expected to walk a quarter of a mile from the house to the church, as he almost always does when he is at his home on his private retreat.

There was no sign of him as the bells rang and the service began in the 18th-century church, where members of the royal family traditionally worship during the winter break.

Buckingham Palace announced last Wednesday that Charles would undergo a corrective procedure next week after being diagnosed with a benign enlarged prostate.

The news came just 90 minutes after Kensington Palace said the Princess of Wales had undergone abdominal surgery and would spend two weeks in hospital.

Kate is said to be 'doing well' after her abdominal surgery at the London Clinic near Regent's Park.

The monarch and Queen Camilla were at his Scottish home Birkhall when they received the shocking news, just after it was revealed the Princess of Wales was in hospital.

King Charles will undergo surgery for an enlarged prostate next week and is currently resting at the Sandringham estate (pictured January 7)

The Princess of Wales is reportedly 'doing well' and will recover in hospital over the next week after a planned abdominal operation

On Monday, during a visit to Swindon, Queen Camilla said the monarch, 75, was doing “fine” when asked by a member of the public.

The couple were flown more than 300 miles on an RAF jet from Aberdeen Airport to RAF Marham on Friday before driving the final 15 miles to Sandringham.

Buckingham Palace shared the news of the king's procedure just 90 minutes after Kensington Palace said Kate had undergone abdominal surgery and would spend two weeks in hospital.

The king, who came to the throne 16 months ago and was crowned in Westminster Abbey last May, will be admitted to an undisclosed hospital.

Camilla revealed the King was doing 'fine' and 'looking forward to getting back to work' when she made a solo visit to the Aberdeen Art Gallery last week.