While Edward and his wife Sophie, Countess of Wessex, 56, are full-time working royals and are likely to continue as such when Charles is king, Andrew withdrew from public life in 2019 and is now thought unlikely to ever return to royal duty.
Princess Anne was gifted the special title of Princess Royal by the Queen shortly before her 37th birthday as recognition for her outstanding service to the crown.
The title will belong to her for life only passing on following her death at which point it is likely to pass on to her great-niece Princess Charlotte, six.
Anne carries out hundreds of engagements every year and has consistently been found to be the Firm’s hardest-working member.
She lives in Gloucestershire on the Gatcombe Park Estate the Queen gave her as a wedding present in 1973.