He allegedly died in 575, rumoured to have lived to the age of 140, after having been assisted in his labors by three successive coadjutors.

It was also suggested that he may have been related to Ambrosius Aurelianus, both of them possibly active in Brittany at some points of their lives.

Medieval sources give Gwynllyw a brother, called "Pawl", who is chief of neighbouring Penychen.

Hywel David Emanuel considered the identification of Paul Aurelian with the Carmarthenshire Paulinus as doubtful.

He is said to have taught Saint Teilo and to have nominated David to speak at the Synod of Llanddewi Brefi (in around 545).

A 6th century inscribed stone found at Caeo in Carmarthenshire, now in the Carmarthen Museum, appears to honour him as "preserver of the faith, constant lover of his country, champion of righteousness".