May have been the brother of Saint Leontius of Frejus; records are unclear. May have been a lawyer. Layman, married to a wealthy widow from Marseilles, France. With mutual consent, both he and his wife entered religious life. Founded the Monanque monastery in Provence (in modern France). Abbot. Bishop of Apt, Gaul (in modern France). Saint John Cassian wrote De Institutis Coenobiorum at Castor’s request.
- Nîmes, France
- “Saint Castor of Apt“. CatholicSaints.Info. 5 August 2009. Web. 6 October 2015. <>