The first St David's Day parade was held in Cardiff as people in Wales and across the world celebrate 1 March.
The organisers said they were angered by the failure of Wales to have its own national holiday and it was time for a "proper festival".
Meanwhile, the Prince of Wales met the Welsh Guards returning from Northern Ireland - and took a tot of the first Welsh single malt whisky for more than a century.
In New York, the Wales International Centre - dubbed an "economic embassy" - was being opened in the prestigious Chrysler Building.
Back home, the organisers of the Cardiff parade said they hoped it would grow in coming years into "a fully-fledged national festival of arts, music, heritage and culture".
The march started in Sophia Gardens near the Welsh Institute of Sport and finished outside the National Museum and Gallery in Cathays Park.
Henry Jones-Davies, chairman of co-ordinators Ymgyrch Treftadaeth Cymru, or the Wales Heritage Campaign, criticised the failure of the UK Government to grant a Welsh national holiday, and said the assembly government was powerless to authorise it.
He added: "The idea of a proper national holiday of the kind enjoyed by other European nations is supported by the vast majority of Welsh people, yet we are not permitted to have one.
"The Irish have consistently and successfully organised inclusive, non-political and joyous celebrations on St Patrick's Day - not only in Ireland but all over the world - and these events have proved positive, unifying, and beneficial influences wherever they have been held.
The Prince of Wales met his own company at RAF St Athan
"It is surely time, in a new, post-devolution Wales for us to do the same. Wales needs a proper festival on its national day."
But Ben Cottam, of the Federation of Small Businesses in Wales said: "We don't have many bank holidays but that shouldn't necessarily be an argument just to pull ourselves in line with the rest of Europe.
"Certainly St David's Day isn't celebrated as much as it should be and in principle no problem, but just not to lose sight of the economic argument in this."
A parade was also held in Colwyn Bay, ending with a service at St Paul's Church.
Also in Colwyn Bay, Presiding Officer Dafydd Elis-Thomas hosted a celebration at the assembly's new north Wales exhibition and visitor centre.
Traditional Welsh food was being served and schoolchildren from Ysgol Bod Alaw, Colwyn Bay, were singing to the guests.
The Prince of Wales began his St David's Day visit to south Wales at RAF St Athan in the Vale of Glamorgan by welcoming soldiers of his Prince of Wales' Company, 1st Battalion Welsh Guards as they arrived home from Northern Ireland after an
The prince then visited the nearby market town of Cowbridge, which was celebrating the 750th anniversary of receiving its royal charter.
The prince salutes a march past at St Athan
From there he attended a service of thanksgiving, meeting residents and community groups and viewing an exhibition on the celebration, which includes
the original charter documents and a letter from Richard III.
Later the prince attended a St David's Day concert by
the BBC National Orchestra of Wales in Cardiff, which has just announced that Charles's patronage has been extended until December 2008.
Before the concert, he met staff of the Welsh Whisky Company and taste the first single malt to be produced in Wales for more than 100 years.
A single malt, Penderyn, is being made at the Gwalia Distillery in the Brecon Beacons National Park by the independently-owned Welsh Whisky Company.
Moving onto a more global flavour, in New York the opening of the Wales International Centre was attended by the UK's ambassador to the UN, Emyr Jones Parry and Welsh Economic Development Minister Andrew Davies.