The church was established as a
mortuary chapel in the 6th century to hold the remains of the nuns of St. Mary Abbey, later the
Abbey of the Holy Cross, which had been founded in Poitiers by Radegund in 552 as the first monastery for women in the
Frankish Empire. Due to its function, the chapel was built outside the city walls, which gave it its initial name, the
Church of St. Mary outside the Walls (). Upon Radegund's death and subsequent burial there in 587, however, the chapel was renamed to be placed under her
patronage. In 955, the church was burned by
Hugh the Great during the siege of Poitiers. The remains of the saintly foundress were exhumed by order of Abbess Béliarde in 1012 for public veneration, and the entire church was rebuilt after a major fire in 1083. The reconstruction expanded the structure, including both a
chevet and the foundations of a bell tower when it was
dedicated in 1099. By this time, the chapel had become both a
parish and
collegiate church, staffed by a community of
canons whose
prior was appointed by the abbess. ==Description==