Prince William and other graduates have been awarded their RAF pilot's wings - by the Prince of Wales.
Prince Charles, accompanied by the Duchess of Cornwall, bestowed the awards at RAF Cranwell, Lincolnshire, in his capacity as Air Chief Marshal.
Flying Officer Wales, training with the RAF since January, was one of 25 graduates to receive their wings.
Prince William, a graduate of Sandhurst military academy, will undertake a similar attachment to the Royal Navy.
The Prince of Wales also awarded trophies to graduates who have excelled in various aspects of the flying course.
He and the duchess also met flying instructors, graduates and their families.
They were later viewing a display of various aircraft, including the Chipmunk T10 trainer plane in which Charles himself learned to fly almost 40 years ago.
Prince Charles trained as a jet pilot at Cranwell in 1971.
Prince Charles learned to fly at RAF Cranwell in the 1970s
He completed his helicopter training three years later.
Like his father, Prince William entered the armed forces after leaving university.
He graduated from Sandhurst Military Academy in December 2006, going on to serve as an officer in the Household Cavalry Blues and Royals.
His intention also to train with the RAF and Navy was announced by Clarence House in October of last year.
William's first solo flight came just eight days into his RAF training, when he piloted a propeller-driven Grob 115 E light aircraft round the airfield at RAF Cranwell.
He then trained on the faster Tucano T1 plane at RAF Linton-on-Ouse in North Yorkshire.
His final placement was at RAF Shawbury, Shropshire, where he learnt to fly the Squirrel helicopter.
William's training periods with the RAF and Navy are familiarisation attachments, aiming to prepare him for his future role at the head of the armed forces.
His shortened training course was designed to make him a competent flier, but an RAF pilot would usually spend up to four years under instruction.
Unlike his brother Harry, he will not become a "career soldier", and is increasingly carrying out public engagements alongside his military duties.