This church, dedicated to the Blessed Virgin Mary, was collegiate; that is, it was served by a college or community of clerics, one of whom had responsibility for liturgy within the church as well as for matters of business. The house where the community lived stands to the south of the church.
The earliest church was built by Sitric, King of Dublin, in 1042. It was replaced around 1235 by a parish church, and then, in the second, half of the 14th century, the present church was built.
The building was modified in the 15th and 16th centuries, when the gables were raised, a bell-cote was built and a new porch and south door were added. The St. Lawrences of nearby Howth Castle also modified the east end to act as a private chapel; inside is the tomb of Christopher St. Lawrence, 13th Baron of Howth, who died in 1462, and his wife, Anna Plunkett of Ratoath.