Prince William has qualified as an operational search and rescue captain in the Royal Air Force, Clarence House has said.
The Duke of Cambridge, who was known as Flt Lt Wales in the military, was only allowed to co-pilot RAF Sea King helicopters but will now be able to command search and rescue operations.
The 29-year-old completed military assessments on 29 May after two days of ground and air-based tests. Mock rescue scenarios included searching for a yacht from the air, carrying out a rescue search for kayakers stranded in the water, and extinguishing a fire on a vessel.
Officer Commanding 22 Squadron, Wing Co Mark Dunlop, said: "Flt Lt Wales demonstrated the required standards needed for the award of operational captaincy. "Due to the nature of search and rescue operations, the required standards are always set at a very high level.
"Operational captaincy carries the overarching responsibility for the safety of the aircraft, its crew and any casualties," Dunlop added.
However, the qualification would not change William's rank and remain as Flight Lieutenant.
"The duke is pleased to have passed the milestone and is looking forward to contributing in a command role to the lifesaving work of the Search and Rescue Force," a spokesperson for William said.
The prince joined C Flight, 22 Squadron at RAF Valley in Anglesey in September 2010. He sparked controversy earlier this year when his six-week programme of search-and-rescue missions in the Falkland Islands angered the Argentinian government, which claimed it was a provocative move in the runup to the 30th anniversary of the Falklands War.
After his fairytale wedding to Kate Middleton, the Duchess of Cambridge, the couple share a home in north Wales near his Anglesey base.