Kate’s appearance demonstrates her continued support for William, with the pair becoming ever popular in the decade since they married in 2011.
Since their wedding, the couple have welcomed to the world Prince George, Princess Charlotte and Prince Louis, and are now the third and fourth most popular royals, YouGov states.
Kate’s commitment to William reportedly came in a “pact” she offered her husband-to-be, as the pair readied themselves for a life of public dedication.
Kate Middleton’s solemn vow to William over relationship: ‘Get too bored – too bad’
Kate Middleton meeting Daniel Craig at the James Bond premiere
Speaking on Amazon Prime documentary Chasing the Royals, Andrew Pierce argued that Kate knew she would need to be by William’s side, and also ensure she was “silent” with regards to matters concerning the Firm.
Mr Pierce remarked in 2010: “She [Kate] has entered into a Faustian pact.
“She will be quiet, she will be obedient, she’ll be dutiful.
“She will look beautiful. She’ll do the right thing. And if she gets too bored — too bad.
“Buy another tiara, bake some more cakes, have another party in Wales, hold a banquet, do some charity work, be a lady who lunches — but you’re not going to rock the boat, you’re not going to brief the media.
“And, unlike Diana, you will not talk to the media directly or indirectly.”
The Royal Family at the James Bond premiere
William is often seen in public as a charming and calm figure, with Kate replicating her husband’s demeanour.
Yet, royal correspondent Camilla Tominey noted how it was Kate that kept William in check, particularly as the Duke of Cambridge had a fiery edge to him.
Ms Tominey felt that the couple had to earn each other’s trust, and that Kate showed a willingness to “not upstage her husband”, while supporting him when he became frustrated.
She told Amazon Prime documentary Kate Middleton: Working Class to Windsor: “I think there is a huge amount of trust there, not just between them, but their circle of friends – their so-called ‘circle of trust’. Their closest friends, who would never dream of leaking anything to press, and really protect them.
“I think equally, one of the secrets of their success of their marriage is that they do seem much more equal than say, for instance, Charles and Diana.
“I think as well Kate has been very careful not to upstage her husband. I think she is the yin to his yang, in that he – although a level-headed, down-the-line kind of guy – can be prone to a few temper tantrums, perhaps.
“And likes to dig his heels in and knows his own mind. I think he can sometimes get quite angry, and one gets the impression that Kate is the one pulling him back, and reining him in, and saying, ‘Alright, let’s just keep calm.'”
The pressure has always been on William to find a wife, particularly as he will one day be monarch.
Royal historian Robert Lacey claimed last year that William was “uncertain” of his relationship with Kate, who he had been dating for around six years in 2007.
The pair had met at the University of St Andrews, and quickly developed a keen friendship, but Mr Lacey said in one phone call this came to an end.
“She shut the door for more than an hour. When she came out, she was single.”
But reports show that less than three months later, the couple started dating again, and within three years would be engaged.
During the documentary Katie Nicholl also detailed the other pressures William was under, as he was forced to choose spending time in either London with his family, or stay with his new military friends, after joining the Armed Forces.
Speaking on the 2011 show, she said: “I think Kate pushed him into a corner. I think she wanted some more commitment. William was hard at work at the military, very busy – he had exams, training.
“He was very involved with his military commitments. And I think at the same time it had become increasingly difficult for them to spend time together.
“William would spend Monday to Friday at the barracks in Bovington, so his time was completely taken up with military commitments, and at the weekends he ended up staying up with his friends, his new Army pals.
“He didn’t want to back to London every weekend.”
Source: EXPRESS CO UK