The Duke of Sussex made an appearance at the Sentebale Polo Cup in Aspen, Colo., on Thursday, where he announced that he will donate $1.5 million of the proceeds from his upcoming memoir to the charity, which benefits children in Africa affected by HIV and AIDS. “This is one of several donations I plan to make to charitable organizations and I’m grateful to be able to give back in this way for the children and communities who gravely need it,” he said in a statement. “The Sentebale Polo Cup is critical to securing the funds needed to advance this important mission, and I’m thrilled to be able to support Sentebale, both in person and financially through a separate charitable donation to meet this immediate need.” The Sentebale Polo Cup is one of Prince Harry’s pet projects, and he’s attended the matches regularly (save for 2020 when it was canceled due to the ongoing COVID-19 pandemic). His pal and Sentebale ambassador Nacho Figueras attended the 2021 match as well, while Meghan Marklereportedly stayed behind at home in Montecito, Calif., with son Archie, 2, and infant daughter Lilibet. Sentebale expressed their gratitude for Prince Harry’s personal donation. The ginger prince co-founded Sentebale with Prince Seeiso of Lesotho in 2006. Harry said of the cause, “Our refocussed mission at Sentebale is about addressing the most immediate needs of vulnerable children in Southern Africa, helping them access vital health services, receive necessary care, and build skills to be more resilient and self-sufficient in the future.” The charity’s work originally focused mostly on Lesotho, but has recently expanded its reach across southern Africa, including Botswana (where Harry and Meghan vacationed and got engaged) and Malawi. In July, Prince Harry announced that he would release a literary memoir through Penguin Random House. “I’m writing this not as the prince I was born but as the man I have become,” he said in a statement at the time. “I’ve worn many hats over the years, both literally and figuratively, and my hope is that in telling my story—the highs and lows, the mistakes, the lessons learned—I can help show that no matter where we come from, we have more in common than we think.” The memoir, scheduled for a 2022 release, will cover Prince Harry’s childhood, military career and marriage to Duchess Meghan, as well as the Sussexes’ leaving their posts as senior royals to pursue a more private life in California. The Duke pledged to donate all of the book’s proceeds to charity. Next, find out who’s playing Meghan Markle and Prince Harry in Lifetime’s Harry & Meghan: Escaping the Palace!