Indeed, “around his seventh birthday”, Prince George was given an insight into his duty-bound future, according to royal historian Robert Lacey.
Prince Louis will also be expected to carry out acts of service and duty to his country when he is older.
However, fifth in line to the throne after Prince Charles, Prince William, Prince George and Princess Charlotte, it is unlikely that the youngest Cambridge will obtain this position.
Prince Louis “unstoppable” but looks to Charlotte for “guidance” – echoes mum & dad
In the same way as perhaps Prince Harry, who was not bound by the same intense protocol that William was growing up, Prince George’s younger brother may have more time for glee and giggles.
Judi observed a difference between the youngest sibling and his older brother and sister. “If George and Charlotte are both capable of showing some understandable signals of shyness as well as a growing sense of duty, Louis looks like an unstoppable, joyful force.”
But despite their differences, Louis slotted into the royal duo effortlessly.
Judi previously told Express.co.uk: “This always appears to be a very calm and well-synchronised sibling dynamic, with no obvious body language traits suggesting status or power jostling or battling for attention.
“There is also the appearance of equality in the trio, suggesting three quite confident children who appear to see no need to over-protect or ‘parent’ one another.”
One slight deviation from this was when Princess Charlotte was pictured cradling little baby Louis on her third birthday.
She was snapped planting a gentle kiss on her brother’s forehead in a “very touching photo”.
But since then Louis “seems to have integrated perfectly into the Cambridge ‘gang’”.
Prince Louis will often copy his older sister’s gestures
Already independent and with his own personality, he has “no apparent need of older sibling protection or support as he rushes about enjoying himself”.
During royal engagements, “he might look to his siblings for some guidance”, and of his two older siblings “it does look as though he sees Charlotte as the instigator”.
The toddler has been spotted on occasion “glancing at her quickly to check before copying her wave and smiling at the camera”.
It is therefore easy to draw parallels here between Prince Louis and Princess Charlotte with Prince William and Kate Middleton.
Most recently on their Caribbean tour, the Prince seemed to experience trepidation and a “deep desire to get things right”, while the Duchess was cool, calm and collected.
During an intimate moment between the pair, Judi James told Express.co.uk: “It was telling that she quickly chatted to her rather tense-looking husband as they stepped out of the plane and her smiles and admiring eye contact look aimed at relaxing him.”
And it’s easy to see why Prince Louis looks to Charlotte in the same way.
Judi concluded: “Not only does she now smile to order but she has always been the most sociable sibling with a love of waving and handshaking that could make her a role-model for Louis.”
Source: EXPRESS CO UK