[5] Isfael was said to have been the son of Budig ap Cybydan, a native of Cornouaille and eventual king of Armorica, and the brother of the martyr Tyfei and Bishop Euddogwy (Oudoceus) of Llandaff.
[7] In Rhygyfarch's hagiography, Isfael was said to have been one of the three principal disciples of Dewi Sant;[4][8][9] in the Book of Llandaff, he is also included among the students of Dubricius and Teilo[6] and said to have succeeded David as the bishop of Menevia (St David's).
The parish churches of St Ishmael's in Pembrokeshire and Carmarthenshire and their surrounding communities are named in his honour.
He was also the patron of the churches at Camrose, Rosemarket, Uzmaston, and (probably) Haroldston St Issells.
[2] A valley or inlet in Carmarthen Bay was previously known as "St. Ismael's Scar".