Susannah Constantine, who used to date King Charles’ cousin David Armstrong-Jones, watches son Joe Bertelsen pass out from Naval Cadets (and Prince William is watching too!)

Susannah Constantine revealed she “couldn’t be more proud” when she shared a photo with her son Joe Bertelsen as he graduated from the Naval Cadets at Dartmouth on Thursday.

The presenter, 61, said on Instagram that her son graduated today as a naval officer from the Britannia Royal Naval College.

Prince William, 41, also appeared for the parade, which saw a total of 202 Royal Navy Cadets pass out, along with International Officer Cadets from Oman, Kuwait, Bangladesh and Trinidad & Tobago.

Susannah is certainly familiar with high society as the mother of three, dated the late queen’s cousin, Viscount Linley, also known as David Armstrong-Jones or the Earl of Snowdon.

In an instant, Susannah, who looked refined and refined in a navy blue suede coat and a cream fur scarf, put her arm around Joe, who looked dapper in a navy uniform and held a sword.

She captioned the post: ‘Couldn’t be prouder… @joebertelsen Naval Officer’

Many rushed to the comments to congratulate Joe, with one person saying: ‘Wow!! Congratulations ⚓️ – what a beautiful photo too! xx’

Another wrote: ‘Congratulations young man. Good looking. You look beautiful, Susannah.’

Someone else said: ‘Fantastic! Huge congratulations!! Great picture!! xx’

Prince William also donned the uniform for the first time in more than a decade when he visited on behalf of King Charles.

He inspected the forward rank of the Guard and the Royal Marines Band of Plymouth, as well as the ranks of the St. Vincent, Howe and St. George Divisions.

He will also meet with staff and cadets on the historic Quarter Deck.

These include those who participated in the parade as well as their instructors.

Prince William, 41, also appeared for the parade, which saw a total of 202 Royal Navy Cadets pass out with International Officer Cadets from Oman, Kuwait, Bangladesh and Trinidad & Tobago.

Susannah herself has a close relationship with the royal family as she dated the Queen’s cousin David Armstrong-Jones for six years in the 1980s.

The cadets undergo 29 weeks of intensive training, progressing from civilians to junior naval officers.

The cadets undergo 29 weeks of intensive training, progressing from civilians to junior naval officers.

They have been tested in a variety of scenarios: in the classroom, on Dartmoor, the River Dart and at sea on board an operational warship.

During his military career, William trained at the Britannia Royal Naval College in 2008, following in the footsteps of his father, King Charles, and grandfather, the Duke of Edinburgh.

The father-of-three was all smiles at the event, wearing a naval uniform which consisted of a trench coat with gold buttons and a navy cap.

Susannah herself has a close relationship with the royal family. She lovingly regarded Princess Margaret as her surrogate mother when she dated her son, David Armstrong-Jones, for six years in the 1980s.

She lovingly regarded Princess Margaret as her surrogate mother when she dated her son, David Armstrong-Jones, for six years in the 1980s.

Speaking on Woman’s Hour in 2017, Susannah explained how her mother, who had a lifelong battle with mental illness, was ‘at her worst’ at the time and Princess Margaret became ‘almost a mother figure’ to her.

She said: ‘I am not tactful or diplomatic… I remember Princess Margaret as incredibly warm and welcoming.

‘My mother was at her worst when I was dating David and Princess Margaret was someone I could turn to.’

Susannah acknowledged Princess Margaret’s reputation as ‘waspish’, adding: ‘She was a very kind woman once you got past the protective front.’

The mother of three, who became a household name after TV show What Not To Wear, revealed how her personal history inspired her first novel, After The Snow, which tells the story of an 11-year-old girl and her whimsical mother.

Susannah said: ‘My mother was manic depressive, I was quite a lonely child and I had one best friend.’ She recalled how her mother’s illness was completely “mismanaged.”

“She has never seen a psychiatrist or therapist,” the style guru said. ‘It’s a devastating condition and it was impossible for my father and obviously for her too.’

Despite the problems it caused, Susannah said she remembers “only good things about her mother.”