 Meanwhile, other accounts credit St Teath to a daughter of Brychan of Brycheiniog named Tedda, Tethe, &c.

In Cornish sources, Tetha was listed among the daughters of Brychan, king of Brycheiniog in Wales, making her the sister of numerous other saints in Wales and Cornwall.She is listed among Saint Breaca's companions, who missionized Cornwall from Ireland around AD 460, by Leland and William of Worcester.Unlike some of her companions, she does not seem to have been martyred by Tewdwr Mawr, the hostile king of Penwith.