On 9 July 1572, nineteen Catholics were martyred in Brielle by the Calvinist William de la Marck, the Lord of Lumey despite an order from the Prince William of Orange to leave priests and religious unharmed. Lumey was the leader of a group of Watergreuzen or “Sea Beggers” – irregular troops that had recently captured the city of Brielle from the Spanish.

The nineteen martyrs included eleven Franciscans, an Augustinians, and a Dominican. The Dominican priest, John of Cologne, had been arrested after it was discovered that he was secretly visiting the other Catholic prisoners to administer the sacraments. After spending several days in prison during which time they were tortured and forced to parody Catholic rituals, the Lord of Lumey demanded that the Catholic prisoners deny the Real Presence in the Blessed Sacrament and the primacy of the pope in exchange for their freedom. The prisoners refused and were martyred by hanging.

Their beatification took place on 14 November 1675, and their canonization on 29 June 1865.