The AC B tells us that David, Dewi in Welsh, was born 30 years after Patrick left Menevia:
“Anus sanctus dewy nascitur anno xxx post dis(c)essum patricii de meneuia.”
As the Irish annals say Patrick arrived in Ireland in 432 it follows that David I was born in 462. This is the David whose ancestry is given in the Welsh genealogies and is spoken of in the Historia Regum Britanniae. His death is mentioned in AC C:
“Sanctus Dauid meneuensis archiepiscopus in domino quieuit .”
The death of the later individual, David II, appears in the AC A and B texts respectively thus:
“Dauid episcopus moni iudeorum.”
“dauid meneuensis episcopus obiit.”
The B text has incorrectly interpreted the A text, the last three words of which are “manu in deorum”, that is “in the hand of God”. So, in reality there is no reference to Mynyw. The date of 601 is not totally inconsistent with the Irish annals which date his obit between 587 and 589. It is this later David whose genealogy appears in ByS 1.
He appears in the Liber Landavensis under the name Deui. Bartrum points out that the V. David 62 tells us:
“According to the Life he died on March 1, the third day after a Sunday.”
He goes on to say
That would probably be Tuesday, perhaps Wednesday … Thus 589 is agreeable with Tuesday and 601 is agrreeable with Wednesday.”
“Neither is agreeable with the suggested date of birth.”
However, §58 claims he reached the age of 147 years, clearly an impossibility. This figure was arrived at by conflating the two Davids. Adding 147 years to the birthdate of David I gives the year 579, that is dlxxix. This was an error for 589, dlxxxix, as a result of losing an x during transcription.
 Bartrum, P.C., MPS (ed.), 2009.