 No historical documents exist to attest the exact construction period of the church of Saint-Maclou.It had a cruciform plan consisting of a nave of five bays accompanied by two single aisles; a transept, each wing of which consisted of two bays; a central bell-tower above the crossing; and a choir of a single bay with a semicircular apse, surrounded by an ambulatory with five radiating chapels.Significant elements of this early church still exist, although their initial character has been lost as a result of reconstruction.