Concerning Virgins (De Virginibus) is a collection of letters, compiled into three “books,” which St. Ambrose wrote to his sister, Manellia, around 377 AD. Written in a rather light-handed non-technical style they appear as ethical guides to women who are thinking of entering nunneries. Concerning Virgins was referred to by other patristic writers including St. Jerome, St Augustine and Cassian, and are included in the writings of the early church fathers.