Peter Phillips opens up about Princess Anne as a grandmother to his and Zara Tindall's kids

The Princess Royal will celebrate her 73^rd birthday on Tuesday, and no doubt she'll be surrounded by her closest family members on her special day.

Princess Anne is mother to Peter Phillips and Zara Tindall, whom she shares with her former husband, Captain Mark Phillips.

The royal also has five grandchildren – Peter's daughters, Savannah, 12, and Isla, 11, and Zara's children, Mia, nine, Lena, five, Lucas, two.

Anne often has a packed schedule with her royal engagements and travels all over the UK, as well as abroad.

But what is the Princess Royal like off-duty?

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In 2020, ITV released a documentary Anne: The Princess Royal at 70, where her children were among the guests who appeared. See the hilarious moment the Princess was joined by the late Queen on a video call that was featured in the programme...

Peter and Zara both reside on Anne's Gloucestershire estate, Gatcombe Park, so they're close-by for family catch-ups.

Speaking about his mother as a grandmother, Peter said in the documentary: "She loves seeing them ride, she loves having them round for Sunday lunches and taking them for walks. Doing all the things that we would do as kids."

"We quite like leaving them on Sundays. We'll say, 'We'll pick them up later, bye.'" Zara joked.

Anne has been spotted having fun with her young grandchildren at the Festival of British Eventing, which is held on her estate annually.

Despite being the late Queen's eldest grandchildren, Princess Anne and and their father Captain Mark Phillips decided not to give Peter and Zara royal titles when they were born.

Peter, who is head of partner acquisition for the sports and entertainment rights agency CSM Sport & Entertainment, said in the documentary: "We were always brought up on the understanding that we were going to have to go to work. We were going to have to go out and earn our, earn our living. Regardless of the fact of who our grandmother was or who our mother was."

Meanwhile, Olympic equestrian Zara added: "I think it made us fight harder as well, to try and be as successful as we could be. So we're very grateful to her not giving us a title anyway."

Speaking about her decision for her children in the programme, Anne said "As a member of the royal family, living with that sort of pressure is hard and the expectations that come with it is hard. And that might have been at the bottom of the list, that it may be less difficult for you. But actually, understanding where they sit within the family and what happens next, it made much more sense."

Peter is currently 18^th in line to the throne, while Zara is 21^st.