The Princess of Wales chose long-favored designers for today’s St. Patrick’s Day parade with the Irish Guards. 
This was the first time the Princess attended the parade as Colonel of the Regiment, an appointment made last December. The Prince of Wales was there in his role as the outgoing Colonel of the Guards; he is now Colonel of the Welsh Guards. 
As you can see, it was a somewhat sodden day. 
After receiving her own shamrock sprig, the Princess was ready to start presenting them to Officers and Guardsmen. 
More about the tradition from the Ministry of Defence.
Although the Irish have observed St. Patrick’s Day for centuries it wasn’t formally celebrated by the British Army until 1900, when HM Queen Victoria decreed the wearing of the shamrock as formal recognition of the bravery of her Irish soldiers during the Boer War.
We return to the MOD’s backgrounder.
On 14 March 1900, Natal Army Orders issued an instruction: ‘Her Majesty the Queen is pleased to order that in future on Saint Patrick’s Day all ranks in Her Majesty’s Irish Regiments shall wear as a distinction a sprig of shamrock in their headdress to commemorate the gallantry of Her Irish soldiers during the recent battles in South Africa’.
Another view. 
A quick video from Rebecca Russell of My London.
The Princess of Wales has arrived at Mons Barracks in Aldershot to take the salute as the Colonel of the Irish Guards on #StPatricksDay 🍀 pic.twitter.com/9ankXe7E59
— Rebecca Russell (@RMRussell29) March 17, 2023
The last to receive his shamrocks is always a favorite, Séamus, the Regiment’s mascot. 
His name is officially “Turlough Mór,” and he was trained with the Royal Army Veterinary Corps.
I believe that is Drummer Adam Walsh, the canine’s handler, in all of these photos with Séamus.
A quick video of Séamus was shared on the Kensington Palace social media accounts.
Walking to get your shamrock on St Patrick’s Day like 🫡 pic.twitter.com/7r0go5mxyS
— The Prince and Princess of Wales (@KensingtonRoyal) March 17, 2023
Another view of the Princess at today’s ceremonies.
After the shamrocks were presented, there was a parade. 
The parade concluded with a Royal Salute and march-past, where the Princess took the salute as the Regiment’s new Colonel.
Both royals also delivered remarks today. As noted by the British Army in its coverage of the event, “Their Royal Highnesses each made speeches, one of thanks and farewell, the other of dedication and promise.”
From Prince William’s speech.
On this, my 13th and final St Patrick’s Day as Colonel, not only am I saddened that I’ll likely fail once again to finish a pint of Guinness… but I am also sad that I won’t in future see more of you, the families, whose unwavering support enables these outstanding men and women to do what they do.”
I’m proud of everything [the regiment] stands for – just as I’m immensely proud of every single one of you. I may be stepping aside, but in Colonel Catherine you have a committed, focused, and already incredibly loyal 11th Colonel.
As you serve together over the years ahead, know that I will continue to watch you, with huge pride in having been one of you.
The Princess then spoke. 
From her remarks:
I really couldn’t be prouder to stand in front of you here today. It really is a true honour to be your Colonel. I am here to listen to you, to support you, and to champion you in all you do – this is a responsibility I do not take lightly.
I look forward to spending more time with you and your families, seeing your commitment to duty and service in all you do.
The Princess referenced a training exercise she took part in with the Guards last week, saying, “All I saw was enthusiasm, pride, and incredible dedication.”
I was hugely impressed with your insistence that nothing is as bad as it seems, and – most of all – your boundless, irreverent, glorious sense of humour. That’s what makes you who you are and what makes the Irish Guards unique.
The Princess also thanked her husband:‘Before I close, however, I want to thank Colonel William. He has always talked about his fierce pride for this Regiment. I know he will continue to support us all in the work we do.” Below, the couple shares a laugh. 
The Guards removed their caps and gave three cheers to the Prince of Wales and then three cheers to their new Colonel, The Princess of Wales.
The Guards noted that “The national saint’s day is a highlight of the Irish Guards’ calendar where all generations gather for a regimental celebration, but to witness the formal handover of responsibilities of Regimental Colonel from The Prince of Wales to his wife, The Princess of Wales, made this year’s event extra special.”
The royals sat for official photographs commemorating the day. 
They also spent time with members of the Regiment. 
And they met family members. 
Below, the Princess with Aoife, age six, and Alice, age four, daughters of Warrant Officer Alistair Wigley and his partner. 
A quick video via The Sun’s Matt Wilkinson.
The new Colonel of the Irish Guards with Aoife, 6, and Alice, 4, daughters of WO2 Alistair Wigley, today in Aldershot pic.twitter.com/kHkSulseVm
— Matt Wilkinson (@MattSunRoyal) March 17, 2023
The Prince and Princess were shown a new regimental painting of the Irish Guards by artist Louise Pragnell, which was painted this year in the state rooms of the Royal Hospital Chelsea. (I think that is Ms. Pragnell on the far left.) 
The Couple visited the Guardsman’s lunch.
And took part in a toast.
The Princess enjoying time with the Guards. 
Now for our look at what the Regiment’s new Colonel wore for today’s ceremonies. 
The Daily Mail reports the style is a Catherine Walker style, showcasing several signature design elements seen in Catherine Walker pieces. The coat features a slim silhouette with princess seams, a stand collar, angled pleats at the upper bodice, a deep back vent, attached waistband, and flared cuffs. The sets of four buttons echo those on the Guards’ uniforms, which are arranged in groups of four.
Beneath the coat, the Princess wore a matching dress. In terms of today’s color choice for the Princess, you can see how vibrant the color was among the brown and black uniforms in a small group photo. 
It also popped in the much larger group pictures. 
More on the color from this People story.
While the Princess of Wales usually marks the event wearing green, the color most closely associated with the holiday, she made a surprising decision to wear a teal Catherine Walker & Co coat dress with matching accessories for the occasion this year.
While the color choice was certainly unexpected, there’s a clever reason for it. Princess Kate’s ensemble perfectly matched the plumes worn in the bearskin caps by the 1st Battalion Irish Guards. The plume being St. Patrick’s blue was selected because that is the color of the mantle and sash of the Order of St. Patrick.
Here you see today’s look and one of the Regiment’s bearskin hats seen for ceremonial parade events. (The photo on the right shows Prince William at Trooping the colour last year.)
More about St. Patrick blue from Smithsonian Magazine:
…the earliest depictions of St. Patrick show him clothed in blue garments, not green, and that when George III created a new order of chivalry for the Kingdom of Ireland, the Order of St. Patrick, its official color was a sky blue, known as “St. Patrick’s Blue.”
More info on the color may be seen here and here.
With thanks to T. Ann and Kate for their comments with the ID, the hat is by Jane Taylor, a bespoke version of the Clio ($1501), described as “A wonderfully romantic hand-sculptured heart-shaped cocktail hat. Made from a luxurious…felt with a matching black pleated crin detail which fans around this stunning-shaped hat.” 
NOTE: The post originally said the hat was a version of the Jane Taylor Vesper style, which is not the case. Thank you to T. Ann and Kate for the heads-up pointing out the correct ID.
The Princess carried a new (to us, at least) clutch by go-to designer Emmy London. It looks like the Natasha clutch in ‘Lake’ suede ($415), with thanks to Middleton Maven for this ID. I do not know who made the gloves carried today. 
The Princess wore coordinating shoes that look like a pair of bespoke Gianvito 105 pumps. Carly from Kate Middleton Style posted an excellent comparison with the brand’s lower-heeled style, the Gianvito 85 in a color called ‘Persian.’ It very much looks like the color worn today by the Princess in the higher-heel height she is fond of. In the montage below, I show the style in the 85mm heel height discovered by Carly; it is available at Savannah’s.
The Princess wore her UFO diamond and emerald earrings. 
The Princess wore the Cartier shamrock brooch owned by the Irish Guards and loaned to royal women taking part in ceremonial duties. I included a photo of the brooch worn on another occasion because it shows the piece’s details much better. On the right is a photo showing the opening on the front of the Princess’s coat used to affix her shamrocks. 
You can just see the opening for the shamrocks in this photo, to the right of the buttons. 
Kensington Palace posted a message on social media following today’s engagement.
From outgoing to incoming Colonel, we will continue to support and champion you in all you do. pic.twitter.com/zFW3wKWaiW
— The Prince and Princess of Wales (@KensingtonRoyal) March 17, 2023
VIDEOS:
The Royal Family Channel offers almost four minutes coverage of today’s events in this video.
In this video from the Press Association’s Catherine Wilkinson, you can hear the band playing music from the Riverdance score.
The band of the Irish Guards plays music from @Riverdance as the Princess of Wales hands out sprigs of shamrock in Aldershot on St Patrick’s Day. pic.twitter.com/aCc66ClXMx
— Catherine Wylie (@wyliecatherine) March 17, 2023
