Is patron of Sithney, near Helston (Cornwall), where William Worcestre saw his tomb. There is still a cult of him at Guissény (formerly Ploesezny) in Brittany. The Life is an uninteresting plagiarism of that of Ciaran of Saighir. According to a Breton folk legend, God one day revealed to him that he was to be the patron saint of girls. He was so alarmed that he asked to be excused the task because they would plague him for husbands and fine clothes and never leave him a moment's peace. He was then asked to look after mad dogs instead. He answered: ‘I'd rather have mad dogs than women any day’; from that day onwards sick and mad dogs have been taken to drink that water of the well of St Sezni. Feast: 4 August.
G. H. Doble, The Saints of Cornwall, ii (1962), 3–14;cf. Anal. Boll., lix (1941), 220–1.