King Charles III addressed the Welsh Parliament on a visit to celebrate 25 years since the then-National Assembly for Wales was established in 1999.

His Majesty said: “I’m 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 that 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.”

Speaking in Welsh, which he learned at Aberystwyth University ahead of his investiture as Prince of Wales, he said: “It is a privilege to share your love for this very special nation.”

The King said it has given him great pleasure to see the bond continue, with the Prince returning to Ynys Mon this week – “a place which I know means so much to him”.

He told the debating chamber or Siambr: “It is with countless special memories and particular pride that I join you as we reflect on the past quarter century of the history we have shared, which you in your work in this Senedd have the great responsibility of making.

“In 1999, when the National Assembly was established, we could not know what lay ahead but we trusted that the common desire for the welfare of the people of Wales would be the surest guide for those who would create, shape and develop this new national institution.

“Looking back … I hope you can feel a real sense of pride in the respect that has been earned and in the contribution that has been made to the lives of so many.

“Welsh minds have indeed been directed to Welsh matters and the distinct voice of Wales is heard with clarity and purpose.

“We look back at the journey so far and we look forward to the journey yet to come.”

Looking to the Plaid Cymru benches in the Siambr, the Kind said: “Now, of course, a parliament would not be worthy of the name were there not differences of opinion.

“But it is a tribute to that spirit of community – so evident to all who love Wales, as we do – that this has been managed with an inclusivity the very shape of this chamber symbolises.”

His Majesty described Wales as a “unique mosaic of places, landscapes and cultures”.

Turning back to Welsh, he said: “It is wonderful to see that the Senedd uses the Welsh language so often – not just as a symbolic act but as its foundation.

“The greatest honour is its use.”

The 25th anniversary coincides with the passing of a law which will see the Senedd expanded from 60 to 96 members elected under a new voting system from 2026.

King Charles said the Senedd has become more than a symbol over the past 25 years: “It has become essential to the life of Wales.

“And as we look back … I offer you heartfelt congratulations on all you have achieved.

“We now look forward to the tasks that we face in the next quarter century – not least the challenge we all share as inhabitants of this threatened planet.

“A challenge which I know you are seeking to meet with energy and determination.

“A great milestone has been reached: there are many more ahead: but you do not travel alone. The strength, resilience and aspiration of the Welsh people will help to sustain you.

“You take with you the goodwill and support of all who have the interests of Wales at heart – they will be equal to any task.

“With those interests in mind, I pray that in the years to come you will achieve even more – overcome even more challenges and find even more causes for celebration.

Wales’ first minister said: “While I was sitting my final exams, another former student of that great Welsh university – another former resident of Pantycelyn hall of residence – was addressing the first National Assembly.

“Your majesty told members: in the Assembly the voice of Wales will have its authentic and vigorous expression, in ways not possible before Welsh minds will be directed to Welsh matters. Indeed, this was the very aim of devolution then as it is now.”

Mr Gething said devolution has evolved into an established part of the constitutional fabric of the UK over the past quarter of a century.

The first minister said Queen Elizabeth told the Senedd in 2003 that it is vital to the health – both of the UK and Wales – that democratic institutions flourish and adapt.