David Thomas, 1802–
It has proved impossible to go back further than this.
This David Thomas is names as the father of David Thomas born born Llanbadarnfaun, Cardiganshire, Wales 1815, when he married Elizabeth Morgans at Llangynfelyn Parish Church, Cardiganshire, on 18/02/1842.
Assuming he was still alive at the time of the wedding (which is uncertain) and assuming he was aged 20 when his son was born (again uncertain) then his year of birth would be 1802 (ucertain).
There are several David Thomas's in the area that were born at about that time, and who also had a son named David Thomas, some of them even living in the same street, so I have been unable to determine which David Thomas is the correct one.
He is presumably dead by the time of his son's marriage in 1842 as he is not listed as a witness, but he may be still alive and working away or infirmed.
Marriage of his son Llangynfelyn Parish Church Marriage Register 18 Feb 1842 David Thomas, of full age, bachelor, Pempombren<b /> Father: David Thomas, Labourer. Elizabeth Morgan, of full age, Spinster, Trataliesin, Father: Edward Morgan, Labourer. Witnesses: John Jones / Pontbrengeifr, Owen Evans / Tre Taliesin