The battalion has chosen the home of Welsh rugby for the first ceremonial event of their anniversary here in the nation they represent.
It will be a celebration of the strong links between rugby and our armed forces, marked throughout the recent Dove Men Series at the Millennium Stadium.
When Wales play England at the start of the RBS 6 Nations tournament next year the famous regimental uniform with the prominent bearskin headgear will play a central role in the day.
Their regimental band will lead the Wales team into the stadium and then play the anthems, flagbearers will unfurl the national colours on the pitch and 70 guardsmen in regimental splendour will line the perimeter of the ground before kick-off.
Lt Colonel Tom Bonas, the Regimental Adjutant, said: “It is a huge honour to be associated with the WRU for this very special landmark in our history.
“We are a rugby regiment having won the Army Cup 13 times and it is wonderful to be linked so closely with the Wales national squad on international day.
“The soldiers will be proud and honoured to be such a central part of the event and it will be something they can tell their grandchildren about.”
He said the anniversary is about history, remembrance and reflection for one of the UK’s most famous regiments.
The Millennium Stadium involvement will launch a year in which the Welsh Guards will feature in a number of formal and high profile anniversary celebration events.
The battalion of some 600 soldiers and 3,000 retired veterans has taken part if all the major conflicts involving the UK since their formation in 1915.
Their links with Welsh rugby have also become strengthened since the Wales international, Ryan Jones, became a Friend of the Regiment even raising £70,000 for the Welsh Guards Afghanistan Appeal during his testimonial year.
WRU Group Chief Executive, Roger Lewis, said: “We are honoured to host what is effectively the launch of the centenary celebrations for the 1st Battalion Welsh Guards.
“This autumn in particular we have all been reminded how rugby and the military have been intertwined through history as we remembered the 13 Welsh internationals who perished during World War I.
“Our remembrance ceremonies here at the Millennium Stadium reflect on all who died in conflict but the associations with our sport are ever present in our thoughts and memories.
“Families from all over Wales will know someone either in the military now or in the past so it is fitting that the home of Welsh rugby becomes the stage on which they can march with pride to mark their centenary.”