Prince Harry will take to a polo field in Florida today to compete in a match in aid of his charity Sentebale.
The event is an annual fund-raising spectacle that has been staged around the globe from New York and Barbados to South Africa and Brazil.
The match for the Sentebale Polo Cup raises money for Sentebale, the Lesotho-based charity Harry founded with the African nation's Prince Seeiso.
The money raised will be used to fund the charity's work supporting vulnerable children and young people living with HIV in Lesotho in southern Africa.
Cathy Ferrier, Sentebale's chief executive officer said: "Great progress has been made over the past few decades to reduce new HIV infections and Aids-related deaths, however adolescents with HIV/Aids in sub-Saharan Africa remain the most at risk.
"The Sentebale Royal Salute Polo Cup is invaluable in allowing us to raise vital funds needed to support these young people, and helps us talk about an issue that urgently needs attention."
The event will be staged at Valiente Polo Farm in Palm Beach an area where the Prince of Wales played polo a number of times in the 1980s.
Harry's charity reached a major milestone last year when it opened its Mamohato Children's Centre in Lesotho - a purpose-built facility to support all of the charity's work with vulnerable children, and specifically host camps delivering psychosocial support to 1,500 HIV-positive young people each year.
Later this week Harry will travel to Orlando ahead of the start of the Invictus Games - the Paralympic-style sporting competition for injured servicemen and women and veterans.
More than 500 competitors from 14 countries will be taking part in the event over five days from Sunday.