There is no record of a parish of Saint-Maclou until 1213, and it was possessed of a double cure until 1736, a peculiarity that could be explained by an older chapel of Saint-Eustache having coexisted for a time with the church of Saint-Maclou, or else by the division of a seigneurial inheritance comprising altar revenues.

The creation of the Val-d'Oise department led to the establishment of the diocese of Pontoise on 9 October 1966 and the consequent elevation of the main church of the episcopal city to the rank of cathedral.

The first study of it appeared in 1587, and it is one of the first five buildings on the territory of the present department of Val-d'Oise to be listed as a historical monument, in 1840.

No historical documents exist to attest the exact construction period of the church of Saint-Maclou.

Significant elements of this early church still exist, although their initial character has been lost as a result of reconstruction.