Irish Guards tunic that threatened to leave Prince William breathless on wedding day on display in Northern Ireland
It was notable by its absence on William and Kate's big day - a tunic, bearing the insignia of the Irish Guards, which was specially made for the Duke of Cambridge's nuptials.
But the man second in line to the throne had a dramatic change of heart after wearing it to his wedding rehearsals.
The heaviness of the fabric, coupled with the threat of searing summer heat on the day of the Royal Wedding, prompted Prince William - who had voiced fears about fainting during the Westminster Abbey service - to opt for a lighter version of the garment.
And now you can see what all the fuss was about because the discarded wedding attire that was literally threatening to take William's breath away is on display at Bangor's North Down Museum.
Now referred to as 'the second tunic', the red jacket - featuring the Irish Guards' distinctive arrangement of buttons in groups of four - is on loan from Regimental Headquarters for royal fashion observers to view ahead of the couple's sixth wedding anniversary on April 29.
Major Simon Nichols MBE, quartermaster of the Irish Guards, who trained both Prince William and HRH Prince Harry at Sandhurst, said he wasn't surprised that the garment was re-designed and remade with reduced padding, sweat pads under the arms and material to absorb the heat.
"Prince William has an affinity with the Irish Guards, which is perhaps why he chose to wear the Regiment's uniform on his big day," said Mjr Nichols, adding that fashion was a factor.
"The style is a bit blingier for the occasion of a wedding that would be watched by the world."
The Major had nothing but praise for Prince Charles' eldest son who, now aged 34, has two children - Prince George (3) and Princess Charlotte (1) - with his 35-year-old wife (formerly Catherine Middleton).
"He is measured, thoughtful and considered and someone who understands the weight of his responsibility," he said.
The senior officer, who is from Northern Ireland, also revealed that he has met the The Duchess of Cambridge on a number of different occasions.
Describing her as "charming" with a "good sense of humour", as well as someone who is also both "personable and easy to talk to", he confirmed that she is every bit "the girl next door" the nation has grown to love.
"We couldn't ask more from someone that will someday be Queen," he added.
"William and Kate are both extremely good ambassadors."
Major Nichols said that Prince Harry (32) actually started his training before his older sibling, meaning that he was more senior in rank to William during his time there.
The Army man also told how there was much debate about which Regiment the brothers would join.
"Prince Harry joined the Life Guards and although Prince William - who is also the Baron of Carrickfergus - contemplated joining the Irish Guards, he eventually joined his brother in the Life Guards," he said.
Military tailors, Kashket and Partners, were the ones commissioned to make William's scarlet Irish Guards colonel's uniform for one of the biggest days of his life.