The Duchess of Cambridge looked at ease as she carried out her first solo military engagement presenting sprigs of shamrock to the 1st Battalion Irish Guards at their St Patrick's Day Parade.
Kate visited the Battalion's home base in Aldershot, Hampshire, to continue the Royal tradition which dates back more than 100 years.
The 30-year-old Duchess wore a green Emilia Wickstead dress coat bought especially for the occasion, with a brown Lock & Co hat, brown suede shoes and a gold shamrock brooch, which has been handed down through the Royal family and was once worn by the Queen Mother.
Kate was greeted by Commanding Officer Major General William Cubbitt before making her way to the parade ground where 450 soldiers, in full ceremonial uniform of scarlet tunics and bearskins, were waiting for her.
Shortly before the Duchess arrived two soldiers had to be escorted from the parade ground when they appeared to faint.
The military band played the first few bars of God Save The Queen as Kate readied herself to present the shamrocks to the 40 Officers and Warrant Officers.
Those Officers then issued shamrocks along the ranks as the band played Irish folk song Carrickfergus.
A spokesman for the Duchess said the origin of the Royal gift of Shamrock dates back to the Regiment's first St
Patrick's Day in 1901, when Queen Alexandra, wife of King Edward VII, requested the shamrock be passed among the men on parade.
Kate also presented a sprig of shamrock to six-year-old Irish Wolfhound Conmeal, the regimental mascot.
Drummer Oliver Vaughey, 22, who has been a dog handler for two-and-a-half years, said: "He was presented with a shamrock by the Duchess of Cambridge. People saw him shake his collar, probably as a thank you.
"He has been our mascot for four years and always marches in front of the regiment."
The Duchess smiled as she was presented with a posy by five-year-old Isabella Stevenson, the daughter of the Regimental Sergeant Major.
Kate also spent time speaking to members of the Regiment Association and the Mini Micks cadets on the parade ground before being photographed with 100 Sergeants and then with 40 Officers.
Before heading off for a private luncheon with Officers at the barracks Kate visited the Junior Ranks Mess Hall where Guardsmen and Lance Corporals cheered and toasted The Duchess with cans of lager and small glasses of Irish sherry.
One soldier said: "Your Royal Highness. On behalf of the 1st Battalion Irish Guards we welcome you and wish you a Happy St Patrick's Day.
"We also thank you for the shamrocks that you have presented to us."
Following the visit, Captain Will Jenkins, 25, who celebrated St Patrick's Day in Afghanistan last year, said it was nice to be at home for the special occasion.
He said: "Last year I was in Afghanistan and the year before that I was in Kenya so this makes a huge difference.
"In Afghanistan I was on operations on HERRICK-13 but we still managed to celebrate St Patrick's Day. We were presented with a shamrock by the senior officer present and we sung a few songs and had a bit of a church service.
"Today has been fantastic. We are very lucky and honoured to have the Duchess here to carry out a long-standing tradition.
"It has always been the history. It's our heritage to be presented with a shamrock."