Catherine holds patronage with more than 20 charitable and military organisations including the Anna Freud Centre, Action for Children, SportsAid, and the National Portrait Gallery.

[34] Despite being offered a place at the University of Edinburgh,[35] Middleton took a gap year, studying at the British Institute of Florence in Italy and travelling to Chile to participate in a Raleigh International programme.

[60] In July 2008, she was a guest at the wedding of Lady Rose Windsor and George Gilman while William was away on military operations in the Caribbean, serving aboard HMS Iron Duke.

[61] In June 2010, the couple moved into a cottage on the Bodorgan Estate in Anglesey, Wales, where William resided during his RAF search and rescue training and subsequent career.

[64] Middleton and William became engaged in October 2010, at a remote alpine cabin on Mount Kenya[65] during a ten-day trip to the Lewa Wildlife Conservancy to celebrate the prince's passing the RAF helicopter search and rescue course.

The announcement was made earlier in the pregnancy than is usual as she had been admitted to King Edward VII's Hospital suffering from hyperemesis gravidarum, a severe form of morning sickness.

[95][96] The speculation largely started after William withdrew from the thanksgiving service of his godfather, Constantine II of Greece, where he was slated to speak, citing an undisclosed "personal matter".

[97] Catherine announced on 22 March, through a video message filmed by BBC Studios, that post-operative tests had found cancer, and the palace said she had been undergoing chemotherapy since late February.

[103] In September 2024, Catherine, in a video message released by Kensington Palace, revealed that she had completed her chemotherapy treatment and that she was looking forward to resuming public engagements in the coming months.

[104] In October 2024, she accompanied William on a visit to meet the families of the victims of the 2024 Southport stabbing, marking her first official public engagement since the completion of her chemotherapy treatment.

[107][108] Middleton's first public appearance with Prince William following their engagement announcement in November 2010 was at a fundraising event organised by the Teenage Cancer Trust in December 2010.

[121] In October 2020, William and Catherine met President Volodymyr Zelensky of Ukraine and First Lady Olena Zelenska at Buckingham Palace, the first royal engagement held at the residence since the start of the COVID-19 pandemic.

[123] In December that year, the couple embarked on a three-day tour of England, Scotland, and Wales via the British Royal Train "to pay tribute to the inspiring work of individuals, organisations and initiatives across the country" in 2020.

[141] The tour was a success, featuring diplomatic engagements such as a visit to the National September 11 Memorial & Museum, the couple's personal interests and attending an NBA match between the Brooklyn Nets and the Cleveland Cavaliers.

[156] The tour was a success, helping promote diplomatic relations with Pakistan while also reflecting the couple's personal interests in climate change and the significance of quality education.

[184] Catherine was also a local volunteer leader with The Scout Association in north Wales,[185] of which Queen Elizabeth II was patron, before being made co-president in September 2020, alongside the Duke of Kent.

[200] In October 2022, she became patron to Preet Chandi, a medical officer in the British Army, who aimed to complete a 1,000-mile solo expedition in the South Pole after finishing a 700-mile journey in the continent earlier that year.

[225] In 2019 she supported workshops run by the Royal Photographic Society in partnership with Action for Children to highlight the effect of photography in expressing thoughts in young people.

[246] She has also highlighted the importance of "a happy home" and "a safe environment" for children, and described her "passion" for the outdoors, referencing it as an asset to building childhood wellbeing and developmental foundations.

[262] She made a surprise appearance on CBeebies Bedtime Stories, where she read The Owl Who Was Afraid of the Dark by Jill Tomlinson as part of the conclusion of Children's Mental Health Week in February 2022.

[266] In December 2024, she and William announced that they were jointly funding a pilot scheme with the charity Norfolk and Waveney Mind to offer extra support for rural and farming communities on the Sandringham estate.

[276] In July 2020, she supported and assisted in the development of BBC's "Tiny Happy People" initiative, providing free digital resources to parents with young children.

[325][326] In July 2007, MPs on the Culture, Media and Sport Select Committee stated that Middleton was the victim of "clear and persistent harassment" by the paparazzi and criticised the lack of intervention by the PCC.

[328][329][330][331] In 2011 close associates of Jonathan Rees, a private investigator connected to the News International phone hacking scandal, stated that he had targeted Catherine during her period as William's girlfriend.

[334] In September 2012, the French edition of Closer and the Italian gossip magazine Chi published photographs of Catherine sunbathing topless while on holiday at the Château d'Autet.

[338] In December 2012, two Australian radio hosts, Michael Christian and Mel Greig, called King Edward VII's Hospital where Catherine was an in-patient for hyperemesis gravidarum.

[341] In October 2014, Catherine and William sent a legal letter to a freelance photographer who had put their son George and his nanny "under surveillance", asking the individual to stop "harassing and following" them.

[342] In August 2015, Kensington Palace published a letter detailing what it stated were the "dangerous" and invasive efforts of the media to get paparazzi pictures of Prince George and Princess Charlotte.

[343] In March 2019, the royal family introduced new rules for followers commenting on its official social media accounts in response to the online abuse aimed at Catherine and her sister-in-law Meghan.

[353] In the same month, the London Clinic initiated an investigation into a potential breach of privacy law after up to three staff members were found attempting to access Catherine's private medical records following her discharge from the hospital.