The Royal, Celestial and Military Order of Our Lady of Mercy and the Redemption of the Captives also known as Our Lady of Ransom (Latin: Ordo Beatae Mariae de Mercede redemptionis captivorum) is a Roman Catholic mendicant order established in 1218 by St. Peter Nolasco in the city of Barcelona, at that time in the Kingdom of Aragon, for the redemption of Christian captives. Its members are most commonly known as Mercedarian friars or nuns.