On 16 Jul 762 Bishop Pehthelm was consecrated Bishop of Whithorn aka Galloway.
Anglo-Saxon Chronicle. 765. This year Eanbert was invested archbishop, on the fortieth day over mid-winter; and Frithwald, Bishop of Whitern, died on the nones of May. He was consecrated at York, on the eighteenth day before the calends of September, in the sixth year of the reign of Ceolwulf, and was bishop nine and twenty winters. Then was Petwin consecrated Bishop of Whitern at Adlingfleet, on the sixteenth day before the calends of August.
Anglo-Saxon Chronicle. 776. This year died Bishop Petwin, on the thirteenth day before the calends of October, having been bishop fourteen winters. The same year Ethelbert was consecrated Bishop of Whitern, at York, on the seventeenth day before the calends of July.
On 18 Sep 776 Bishop Pehthelm died.