Charles, who was taught Welsh at the University College of Wales at Aberystwyth in 1969, addressed members of the Welsh Parliament in a remembrance event at the Senedd, as part of the King and Queen Consort’s tour of the UK nations.
Speaking bilingually, the King said his mother, the Queen, was immensely proud of Wales and was devoted to the country.
“I take up my new duties with immense gratitude for the privilege of having been able to serve as Prince of Wales,” he said.
“That ancient title dating from the time of those great Welsh rulers like Llywelyn ap Gruffudd, whose memory is still rightly honoured, I now pass to my son William, whose love for this corner of the earth is made all the greater by the years he himself has spent here.”
Arriving at the Senedd, Charles and Camilla were received by the Lord Lieutenant of South Glamorgan, Morfudd Meredith, Llywydd Elin Jones, and First Minister Mark Drakeford.
Hundreds of people, including schoolchildren, waited outside waving Wales flags and chanting ‘We want the King!’ ahead of their arrival.
After entering the building, the King and Queen Consort were greeted by a fanfare from the trumpeters from the band of The Royal Welsh.
Harpists also played as the couple moved through the Senedd towards the Siambr – the debating chamber.
The royal party were met by the Mace Bearer, Shahzad Khan, and Wales Herald of Arms Extraordinary Tom Lloyd, who led the group to the Siambr.
Addressing the Senedd, the Llywydd said the Queen’s last visit was only 11 months ago at the official opening of the sixth Senedd.
“The Queen was on fine form that day. Many members shared their anecdotes of that visit when we met to pay tribute to the Queen and discussed our motion of condolence in the Senedd on Sunday,” Ms Jones said.
“The stories and tributes paid by members to the Queen when we convened on Sunday were warm and witty.
“As you may imagine, there were many mentions of corgis – her constant, lifelong Welsh companions.
“And of course the members here representing Pembrokeshire were particularly keen to champion her preference for the Pembrokeshire corgi.
“And the member for Ceredigion, me, was silent, and ever so slightly jealous, of the Queen’s choice of the Pembrokeshire corgi over the Cardiganshire corgi.”
She added: “It is my sincere hope that the modern relationship between this Senedd, this country and the royal family will be rooted in respect and sustained by understanding.
“And as we remember today the Queen’s enduring commitment to our parliament, we also look forward to the King’s future association with the Senedd and our work on behalf of the people of Wales.”
Before leaving, Charles and Camilla met members of the Senedd before Osian Powell, 11, of Ysgol Gymraeg Hamadryad in Butetown, presented the Queen Consort with a posy.
When the couple left the building to meet people outside there were boos from Welsh nationalist protesters, who held up signs with the name of Owain Glyndwr.
Their jeers were quickly drowned out by people singing God Save The King.
Speaking afterwards, Osian, who was accompanied by his mother Jess Huckson, said the Lord Lieutenant of South Glamorgan had calmed his nerves ahead of meeting the royal couple.
“It was really exciting and was worth the wait,” he said.
“I just said ‘Hi’ and the King said ‘Hi’, and said he hoped I got on well in life.”
Osian said it was nerve-wracking but he would remember the moment for a long time – having feared he was in trouble when he found out he had been picked to present the posy.
“My teacher told me the head teacher wanted to see me and I went down there thinking I was in trouble,” he said.
“She asked me if I wanted to give the posy to the Queen.”