Gaude Mater Polonia
Gaude Mater Polonia was one of the most significant medieval Polish hymns, written in Latin between the 13th and the 14th century to commemorate Saint Stanislaus, Bishop of Kraków. Polish knights sang and chanted the hymn after victory in battle, presumably to one of the Gregorian melodies associated with the Eucharistic psalm O Salutaris Hostia on which it is based.