Prince Harry will begin a five-day visit to Singapore and Sydney on Sunday to promote causes close to his heart - supporting wounded military and veterans, and children in Africa living with HIV and Aids.
In Singapore Harry will stage the Sentebale Polo Cup in aid of his charity of the same name, and later travel to Australia to launch the 2018 Invictus Games which will be hosted by Sydney.
The charity polo match has become an important annual fundraising event for Sentebale, a charity which works with children in Lesotho and Botswana who are coming to terms with being HIV positive, have Aids or have lost their parents to the disease.
The sporting event will be held at the Singapore polo club on Monday and usually features international professional players who take on a team led by Harry, a keen amateur.
Cathy Ferrier, Sentebale's chief executive officer, said: "Since Sentebale was founded in 2006, the charity has reached thousands of children and young people in Lesotho, and latterly in Botswana, who have been struggling to come to terms with living with HIV by addressing their mental health and wellbeing.
"It is our ambition see a reduction in the number of new HIV infections and Aids-related deaths amongst adolescents in southern Africa, by putting youth first and equipping them with skills and relevant wraparound support that they need to lead healthy, productive lives."
A 2004 gap year trip to the landlocked African nation of Lesotho inspired the prince to set up his charity two years later with the country's Prince Seeiso, younger brother of King Letsie III.
Their aim was to help youngsters in need and other children who had lost one or both parents to Aids or contracted the disease themselves.
In November 2015 Sentebale opened its £2 million Mamohato Children's Centre in Lesotho to scale up its Mamohato camps, a residential project providing psychological, social and practical support to children struggling to cope with being HIV positive.
Harry will begin his visit to Singapore by attending an Aids reception at Eden Hall where he will watch a rapid HIV test and then meet privately with HIV patients before joining a reception.
The prince will later visit a community event where he will watch some martial arts.
In Sydney on Wednesday, the prince will attend events to celebrate the city's hosting of the 2018 Invictus Games, the international sporting competition for wounded, injured and sick service personnel and veterans founded by the prince in 2014.
The Invictus Games, which this year will be held in Toronto, Canada, has been the other main long-term focus of Harry's public work, and he is patron of the Invictus Games Foundation, which oversees the delivery of the tournament.
In Australia in 2018, more than 500 competitors from 17 nations will compete in 11 adaptive sports across Greater Sydney, including Sydney Olympic Park and on and around the city's harbour.