The King has celebrated 25 years of Welsh devolution as he addressed the Senedd, saying his "respect and affection for the people of this ancient land" had "deepened with every passing year".
In a speech peppered with Welsh, Charles described the anniversary as a "significant milestone" and spoke of the "great change" that had occurred over the quarter of a century.
The King, who was visiting Cardiff with the Queen, told Senedd members that the Welsh Parliament had become essential to the life of Wales.
The former Prince of Wales also touched upon his pride in seeing his son, the current Prince of Wales, continue his relationship with the country.
Charles, who spent nine weeks at the University of Aberystwyth learning Welsh when he was 20, began by thanking the Llywydd -- the Speaker -- and First Minister Vaughan Gething and gathered politicians in Welsh.
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He added: "The Queen and I are so delighted to join you today as we mark this significant milestone in our history -- the 25th anniversary of Welsh devolution.
"It is a milestone on a journey which it has been my privilege, all my life, to share with you.
"During times which have seen great change, profound sorrow, and tremendous achievement. Through it all, my respect and affection for the people of this ancient land have deepened with every passing year."
He added: "Over the last 25 years, the Senedd has become more than a symbol.
"It has become essential to the life of Wales.
"As we look back over the last quarter-century in the long journey of our history, I offer you my heartfelt congratulations -- llongyfarchiadau mawr -- on all you have achieved."
The King said of heir to the throne William: "It has given me great pleasure to see my son's relationship with this special land continue, including returning only this week to Anglesey -- Ynys Mon -- a place which I know means so much to him."
Charles gave the Prince of Wales title to his son the day after acceding to the throne, announcing the decision in his first televised address to the nation.
It is the monarch's first visit to the Welsh Parliament since September 2022, when he received a motion of condolence after the death of the late Queen.
Troops from the Royal Welsh formed a guard of honour and the royal party was greeted by children representing schools across Wales.
Camilla, who was dressed in an Anna Valentine pale pink coat dress and Lock \& Co straw hat, wore a leek brooch in celebration of the country's national emblem.
The King affectionately praised Wales as a "unique mosaic of places".
"What a country you have to serve. What a unique mosaic of places, landscapes and cultures is entrusted to your care," he said.
Charles added: "Welsh minds have indeed been directed to Welsh matters, and the distinct voice of Wales is heard with clarity and purpose."
And he praised the Senedd's use of the Welsh language, saying in Welsh: "It is -- if I may say so -- very good to see that the Senedd makes so much use of the Welsh language. Not just as a symbol. But as an essential. The best way to show honour is to make use."
The King's new harpist, Mared Pugh-Evans, gave her first performance in the position during the celebration.
Camilla was presented with a posy by 10-year-old Celyn Matthews-Williams, a Covid community champion from Llanelli, South Wales.
During the pandemic, the youngster raised money for food banks and the Wales Air Ambulance and brought joy to her community by growing sunflowers and setting up a book exchange on her garden wall.
The visit coincides with a new law which will see the size of the Senedd increase to 96 members from 2026.
