When Prince William is crowned King, the royal family are in for a fair few changes.
First, Kate Middleton will be named Queen Consort or 'Queen Catherine', Prince George will bump up a spot in the line of succession to the British throne, and Princess Charlotte will become the Princess Royal - BUT the young royal won't inherit the title straight away.
The title of Princess Royal is already held by a member of the royal family, so Charlotte cannot inherit the title until it's available.
'The title of Princess Royal is traditionally bestowed on the eldest daughter of the monarch,' royal expert and author of Prince Harry: The Inside Story Duncan Larcombe tells TownandCountrymag.com, pointing out that Princess Anne, Queen Elizabeth II's eldest daughter, is the current Princess Royal.
Larcombe adds, 'It is a title that remains for life, so Princess Charlotte will have to wait at least until the death of the current Princess Royal.'
However, even after Princess Anne's death, there is no guarantee that Charlotte will adopt the title.
Larcombe claims it will then be up to Charlotte's father, William, to decide if and when Charlotte gets the title.
This is not a new tradition, as Princess Anne also had to wait for the title - over 20 years to be exact.
'Princess Anne had to wait until 1987 before her mother the Queen bestowed the title of Princess Royal on her, even though the title had been vacant since 1965,' Larcombe says.
The title previously belonged to Princess Mary, eldest and only daughter of and , who was Princess Royal from 1897 to 1965.