Born: 24 September 1840, Argentina
Died: 9 July 1920
Country most active: Argentina
Also known as: María Luisa de las Mercedes Castellanos de la Iglesia
Argentine aristocrat and philanthropist Mercedes Castellanos de Anchorena is known for comissioning the San Martín Palace and funding the construction of the Basilica of the Holy Sacrament, the Monastery of Saint Teresa of Jesus, and the Cathedral of Salta, as well as providing scholarships to students at the Pontifical Latin American College in Rome.
In 1903 she founded the town of Aarón Castellanos (named for her father) in Santa Fe; she also funded the construction of a Franciscan convent and hospital there.
In recognition of her dedication to Catholic charities Pope Pius XI named her Marquesa de La Iglesia Católica (the first Argentine to be made a papal marchoiness) and awarded her a Pontifical Golden Rose.