Martyrium of Saint Denis, Montmartre, Religious crypt in Montmartre, France

The Martyrium of Saint Denis is a crypt chapel built in 1884–1887 in the chapel of the Helpers of the Holy Souls on rue Yvonne Le Tac, on the site of the Lower Abbey of Montmartre. It stands on the perimeter of the parish of Saint-Pierre de Montmartre and holds three graves marked with crosses and ancient inscriptions, found during 16th-century construction work.

A chapel was built around 475 where Saint Denis, first bishop of Paris, was martyred; it was rebuilt in the 9th century. Bones of Christians buried on the hill were gathered in a quarry, called the Martyrium or champ des morts. In the 16th century, construction exposed a crypt with three graves marked with crosses and inscriptions, which the abbesses of Montmartre Abbey enclosed with the Sanctum Martyrium Chapel. The abbey and chapel were destroyed during the French Revolution; the present crypt was built in 1884–1887 and blessed on 15 August 1887.

On 15 August 1534, Ignatius of Loyola, Francis Xavier, Pierre Favre and four companions pronounced vows of poverty and chastity in the Martyrium and promised a pilgrimage to Jerusalem. Favre, the only priest among them, received the vow while giving communion. This Vow of Montmartre began the Society of Jesus, approved by the bull Regimini militantis ecclesiae in 1540.

Access is typically available on specific days, so you should check in advance with the managing association for opening times. The underground location means you will need to descend stairs to reach the chapel.

The crypt now standing was built in 1884–1887 inside the chapel of the Helpers of the Holy Souls, a congregation founded by Eugénie Smet (1825–1871). It was blessed on 15 August 1887 by the Archbishop of Paris and keeps alive two memories: the martyrdom of Denis and the Vow of Montmartre.