The Duke of Cambridge has flown to Kenya to attend the wedding of a close friend and learn more about wildlife conservation projects.
William will be among the guests when long-term pal Jessica Craig marries Jonathan Baillie, conservation programmes director at the Zoological Society of London, this Easter weekend.
In 2003 St James's Palace took the unusual step of denying William was romantically attached to Miss Craig, the daughter of a wealthy Kenyan conservationist.
The palace poured cold water on reports the Duke had fallen for her during his gap year in 2001 when he visited the east African nature reserve, Lewa Wildlife Conservancy, her father co-founded, saying they were just friends.
They have remained close friends and William even proposed to wife Kate at Lewa while the pair were on a romantic break in October 2010.
Kensington Palace did not comment on whether the Duke would be attending the wedding, as has been widely reported, but it is understood William will be joining the guests.
Last week William responded to media accusations he is work-shy by saying such criticisms were "part of the job''. He has been working this week as a helicopter pilot with East Anglian Air Ambulance and is due to return to work next week after the Easter break.
In a statement the palace said the four-day trip was private and would begin on Thursday with the Duke meeting the president of Kenya. The trip is being funded privately.
Kensington Palace said: "The meeting is taking place at the request of Her Majesty's Government, and His Royal Highness is pleased to have the opportunity to meet the president while he is in Kenya.
"They will discuss the relationship between the United Kingdom and Kenya, to deepen relations between the two countries on a broad range of topics including defence and security, and conservation."
An ambitious project, championed by William, to shut down illegal trafficking routes was launched last week.
Leading figures from conservation charities, airliners, shipping organisations and other bodies signed up to a declaration committing them to major steps to tackle smugglers moving rhino horn, ivory and other endangered animal parts for huge profits.
William is royal patron of the wildlife conservation organisation Tusk Trust and after meeting the president he will spend the remainder of the day seeing first-hand some of the long standing conservation and anti-poaching initiatives taking place in Kenya which are supported by the trust.
The Duke will watch vets at work in the field as they fit radio tracking collars to elephants to help with research and conservation.
At Lewa, William will spend time with a team of rangers to learn about their work protecting one of Africa's significant rhino populations from poaching.
Miss Craig's wedding will take place on Saturday and William will spend the rest of his time in Africa privately.