This is the highest figure for any royal, though many engagements took place virtually due to coronavirus.
Speaking to the Daily Telegraph, the insider said: “The public does get the royals and over time, you can’t fool anyone.
“Princess Anne is universally respected because she is who she is – and I think it’s the same with Camilla; what you see is what you get.
“She’s unselfconscious, unpushy and on message, and she gets on with the job.
“She’s respected and admired and liked a lot – some people may now even love her.”
In the number of royal engagements conducted in 2020, Princess Anne was followed by Prince Charles.
The future king undertook 146 engagements over 141 days.
Darren Best, from commercial property agents Savoystewart.co.uk, analysed the figures.
He commented: “For many generations, the royal family’s fierce dedication to serving the crown has been one of their greatest legacies, and our findings clearly indicate that age is no obstacle for the most senior members of ‘the Firm’.
“The Queen’s commitment to lifelong service has been an example to her daughter Princess Anne and her ultimate successor, Prince Charles, who follows closely in her hardworking regal footsteps.”
Anne, like her mother, is a keen equestrian and competed in the 1976 Olympic Games representing Great Britain.
She has two children, Peter Philips and Zara Tindall, born in 1977 and 1981 respectively.
A documentary on the Princess Royal, “Anne: The Princess Royal at 70”, is now available to watch on True Royalty TV.
Speaking to Fox News Nick Bullen, co-founder of True Royalty TV, said: “Princess Anne is a fascinating and beloved character in Britain.
“She’s probably the hardest-working member of the royal family who takes on the most engagements.
“She’s survived a kidnapping, she participated in the Olympics.
“She also gained an international fan base thanks to ‘The Crown,’ on Netflix, which has portrayed her as strong-willed but overshadowed by her brothers.
“Her story is a great one worthy of being told.”
In 1971 Anne, riding her horse Doublet, won the European Championship individual gold eventing medal.
The same year she was voted the BBC’s Sports Personality of the Year.
Mr Bullen added: “I’ve been lucky to film Princess Anne a few times and she is absolutely fantastic.
“She’s never cared for celebrity. And I believe that’s what people admire the most about her.”
Source: EXPRESS CO UK