This only son of Prince Andrew of Greece became a British subject in 1947 & gained a dukedom
The Duke learned to fly with the RAF at White Waltham and gained... [DOC] [TLE] Why we'll never see 'Princess Catherine'  Royal Central [PAR] Aug 2, 2013 ... She would become HRH Prince Henry of Wales or HRH The Duchess of Sussex 
.... Only then comes Prince Andrew, now sixth in line.