LONDON — Britain's Prince William is due to take his final flight as an air ambulance pilot Thursday, as the second-in-line to the throne prepares to take on more royal duties to support his 91-year-old grandmother, Queen Elizabeth.

William, 35, has spent two years flying medevac missions for the East Anglia Air Ambulance in southeast England. Previous to this he served for seven years in the Royal Air Force, gaining his wings in 2008 and working as a search-and-rescue helicopter pilot from 2009 to 2013.

But after more than a decade living a relatively normal life, the royal family announced in January that William and his wife Catherine, the Duchess of Cambridge, would step up their royal duties.

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"I wanted to say thank you to my colleagues, team mates and the people of East Anglia who I have been so proud to serve." — Kensington Palace (@KensingtonRoyal) July 27, 2017

The move comes as William's grandfather, Prince Philip, is set to retire in the fall. The 96-year-old Duke of Edinburgh is a highly visible royal, carrying out 336 official appearances in 2016 to William's 204 in the same year.

The palace has afforded William a great degree of freedom to have a regular job and live with his family at Anmer Hall, a country house in Norfolk, near to where the East Anglia Air Ambulance is based.

Prince William, Duke of Cambridge starts his final shift with the East Anglian Air Ambulance based out of Marshall Airport on July 27, 2017 near Cambridge, England. Heathcliff O'Malley / Pool via Getty Images

Speaking to NBC News when Prince Philip announced his retirement, Gordon Rayner, who spent seven years as royal correspondent for Britain's Daily Telegraph, said William has been shielded from royal duties in order to allow him to bring up his family in private.

"William has a young family and it [being monarch] is a huge burden," Rayner said. "William has already been seen by some as a reluctant royal and Charles will want to be able to allow him to bring up his children as privately as possible behind closed doors."

Prince William and his wife Kate, the Duchess of Cambridge, and their children Prince George and Princess Charlotte on the tarmac of the Airbus compound in Hamburg, Germany on on July 21,2017. Patrik Stollarz / AFP - Getty Images file

But despite Anmer Hall remaining the couple's official residence, the royals announced they will be spending more time at Kensington Palace — their official London residence — when William leaves his post. Four-year-old Prince George will also begin school in London in September, after previously attending a Montessori preschool in Norfolk.

"Their Royal Highnesses are keen to continue to increase their official work on behalf of The Queen and for the charities and causes they support, which will require greater time spent in London. Prince George will begin school in London in September and Princess Charlotte will also go to nursery and eventually school in London as well," a royal press statement read in January.

The Duke of Cambridge will complete his last shift as an air ambulance helicopter pilot with the @EastAngliAirAmb this evening. pic.twitter.com/x8mbgNJlZU — Kensington Palace (@KensingtonRoyal) July 27, 2017

Speaking in January William said: "It has been a huge privilege to fly with the East Anglia Air Ambulance. Following on from my time in the military, I have had experiences in this job I will carry with me for the rest of my life, and that will add a valuable perspective to my Royal work for decades to come.

"I would like to thank the people of East Anglia for being so supportive of my role and for letting me get on with the job when they have seen me in the community or at our region's hospitals. I would especially like to thank all of my colleagues at EAAA, Babcock, and Cambridge Airport for their friendship and support. I have loved being part of a team of professional, talented people that save lives every day. My admiration for our country's medical and emergency services community could not be any stronger."