There aren't many facts about St David; but here are the only undisputed ones:

He really existed
He was at the heart of the Welsh church in the 6th century
He came from an aristocratic family in West Wales
His mother was a saint, Saint Non
His teacher was also a saint, St Paulinus
He founded a large monastery in West Wales
He was one of the early saints who helped to spread Christianity among the pagan Celtic tribes of Western Britain
He became Archbishop of Wales, but remained in his community at Menevia (now called St Davids)
He was active in supressing the Pelagian heresy
His shrine became a great place of pilgrimage; four visits to the shrine at St David’s was considered the equivalent of two to Rome, and one to Jerusalem!
The most famous story about Saint David tells how he was preaching to a huge crowd and the ground is said to have risen up, so that he was standing on a hill and everyone had a better chance of hearing him.

St David's Day has been a national festival in Wales since the 18th century, and is still marked with gusto.

Many people will wear either a daffodil or a leek, which are both symbols of Wales.

The other Welsh symbol, Y Ddraig Goch (the Red Dragon, Wales's national flag), will be flown on many more buildings than usual.

Concerts are held to mark the occasion, particularly male voice choirs.

Any Cymry (Welsh folks) here who can share with us how they celebrate the holiday? Is it as big an occasion in Wales as St. Patrick's Day is in Ireland?