Ambrosian chant (also known as Milanese chant) is the liturgical plainchant repertory of the Ambrosian rite of the Roman Catholic Church, related to but distinct from Gregorian chant. It is primarily associated with the Archdiocese of Milan, and named after St. Ambrose much as Gregorian chant is named after Gregory the Great. It is the only surviving plainchant tradition besides the Gregorian to maintain the official sanction of the Roman Catholic Church.