About St David
Saint David (c. 500-589) (known in Welsh as Dewi Sant) was a church official, later regarded as a saint and as the patron saint of Wales. His birth date is still controversial, with suggestions ranging from 462 to 512.
Rhygyfarch, the late 11th century author of the saint's life story (see http://en.wikipedia.org/wiki/Saint_David), wrote that David was the son of sanctus rex ceredigionis, where Sanctus has been interpreted as a proper name and its owner honoured by Welsh Christians as Sandde, King of Ceredigion. However, this Latin phrase can equally well mean simply "holy king of Ceredigion". The king of Ceredigion around the time of David's birth would have been Usai. According to Rhygyfarch, Sandde was his brother, so probably only a king of part of Ceredigion. They were sons of King Ceredig, founder of Ceredigion.
It is claimed that David lived for over 100 years, and he died on a Tuesday 1 March (now St David's Day). It is generally accepted that this was around 590, making the actual year 589. The monastery is said to have been 'filled with angels as Christ received his soul'.
His last words to his followers were in a sermon on the previous Sunday. Rhygyfarch transcribes these as 'Be joyful, and keep your faith and your creed. Do the little things that you have seen me do and heard about. I will walk the path that our fathers have trod before us.'
Taken from Wikipedia's article on St David.