He is assigned a brother Matócc, who in later hagiographical tradition appears as an ecclesiastic associated with Inis Ulad (near Donard, Co. Wicklow). Another account refers to a Bishop Sanctán and his brother Lethnán; they are represented as sons of Cantón, who is described as a British king; some variants of this tradition add Matócc as a third brother. There seems to be some confusion: perhaps the two accounts refer to the same Sanctán, the different names accorded to his father and siblings arising as his cult diffused from one locality to another. Sanctán is included in the list of bishops in the Book of Leinster. His principal foundation was Cell dá Less (the church of the two enclosures), which is unlocated. He was also associated with Cell Espuicc Sanctáin; the placename survives in corrupted form as Kill St Ann (Glenasmole, Co. Dublin). His cult was brought to the Isle of Man, where he is commemorated in the name of Santon parish. The year of Sanctán's death is not recorded; he probably died on 9 May, the date on which he is entered in the martyrologies.