Saint Caillin (fl. c.570) was an Irish medieval saint and monastic founder. His Feast day is celebrated on 13 November. The patron saint of Fenagh, County Leitrim, Caillin was born in the 6th century and founded a monastic settlement at Fenagh. His history was given in the Old Book of Fenagh (no longer extant; material included in the Book of Fenagh). The Annals of the Four Masters mention of him living in 464 is based on the very late unreliable 16th century Book of Fenagh. All his siblings lived in the second half of the 6th century so it is likely Caillín lived at the same time. This date is also supported by his position in the Irish genealogies and by the Life of Saint Mogue (born c.560), who was taught by Caillín. Life Caillin was born in Conmaicne Dun Mor (now north County Galway). Caillin's mother's name was Dediva (also called Editua or Dedi or Deidi or Deighe or Deidiu or Deaga), daughter of Tren, son of Dubhthach moccu Lughair, who was Chief Ollam of Ireland and royal poet of King Lóegaire mac Néill. Dediva's other children were Saint Senan of Laraghabrine, son of Fintan, Saint Diarmaid the Just, son of Lugna, St.Mainchín of Corann, son of Collan of Corann, Saint Felim of Kilmore son of Carill, Saint Daigh of Inniskeen son of Carill, Saint Femia daughter of Carill and Senchán Torpéist, another Chief Ollam of Ireland. Caillin was the third eldest of Dediva's children. Caillin had another brother named Nisi Mac Niata, whose death left a legacy for Caillin. Saint Fintan and Rome Caillin studied under St. Fintan. To complete his studies he went to Rome and for this journey St. Fintan gave him 300 ounces of solid red gold. At the end of a long period of study in Rome he returned, bringing with him relics of the apostles and a cloth made by the Virgin Mary and used when she fed the infant Jesus. According to the Book of Fernagh, Caillin returned to Ireland twelve years after the arrival of Patrick, who later consecrated him bishop. Fenagh abbey He founded a monastic site at Fenagh, County Leitrim, which was then the territory of the Conmhaícne Magh Rein, part of the overkingdom of Breifne. He became the patron saint of Fenagh and the Conmaicne of Magh Rein. An angel was sent to Caillin to show him the