He was the son and heir of Giles Daubeney, 1st Baron Daubeney (1451-1508), KG by his wife Elizabeth Arundell, the daughter of Sir John Arundell of Lanherne, Cornwall.
Mawgan Porth is in the civil parish of Mawgan-in-Pydar at the seaward end of the Vale of Lanherne (or Vale of Mawgan) where the River Menalhyl discharges into the sea.
The Arundells of Lanherne, Cornwall, and of Chideock, Dorset, are descended from Sir Thomas Arundell's elder brother, Sir John Arundell (c.1550-1557) of Lanherne.