The year 1572, Luther and Calvin had already wrested from the Church a great part of Europe. The iconoclastic storm had swept through the Netherlands, and was followed by a struggle between Lutheranism and Calvinism in which the latter was victorious. In 1571 the Calvinists held their first synod, at Embden. On 1 April of the next year the Watergeuzen (Sea-beggars) conquered Briel and later Vlissingen and other places. In June, Dortrechtand Gorkum fell into their hands and at Gorkum they captured nine Franciscans. These were: Nicholas Pieck,guardian of Gorkum, Hieronymns of Weert, vicar, Theodorus van der Eem, of Amersfoort, Nicasius Janssen, of Heeze, Willehad of Denmark, Godefried of Mervel, Antonius of Weert, Antonius of Hoornaer, and Franciseus de Roye, of Brussels. To these were added two lay brothers from the same monastery, Petrus of Assche and Cornelius of Wyk near Duurstede. Almost at the same time the Calvinists laid their hands on the learned parishpriest of Gorkum, Leonardus Vechel of Bois-le-Duc, who had made distinguished studies in Louvain, and also has assistant Nicolaas Janssen, surnamed Poppel, of Welde in Belgium. With the above, were also imprisoned Godefried van Duynsen, of Gorkum who was active as a priest in his native city, and Joannes Lenartz of Oisterwljk, an Augustinian and director of the convent of Augustinian nuns in Gorkum. To these fifteen, who from the very first underwent all the sufferings and torments of the persecution, were later added four more companions: Joannes van Hoornaer, a Dominican of the Cologne province and parish priest not far from Gorkum, who, when apprised of the incarceration of the clergy of Gorkum, hastened to the city in order to administer the sacraments to them and was seized and imprisoned with the rest, Jacobus Lacops of Oudenaar, a Norbertine, who after leading a frivolous life, being disobedient to his order, and neglectful of his religious duties, reformed, became a curate in Monster, Holland and was imprisoned in 1572; Adrianus Janssen of Hilvarenbeek, at one time a Premonstratensian and parish priest in Monster, who was sent to Brielle with Jacobus Lacops; and lastly Andreas Wouters of Heynoord, whose conduct was not edifying up to the time of his arrest, but who made ample amends by his martyrdom.
After enduring much suffering and abuse in the prison at Gorkum (26 June-6 July) the first fifteen martyrs were transferred to Brielle. On their way to Dortrecht they were exhibited for money to the curious and arrived atBrielle 13 July. On the following day, Lumey, the commander of the Watergeuzen, caused the martyrs to be interrogated and ordered a sort of disputation. In the meantime the four other martyrs also arrived. It was exacted of each that he abandon his belief in the Blessed Sacrament and in papal supremacy. All remained firm in their faith. Meanwhile there came a letter from William of Orange which enjoined all those in authority to leavepriests and religious unmolested. Nevertheless Lumey caused the martyrs to be hanged in the night of 9 July, in a turfshed amid cruel mutilations. Their beatification took place on 14 Nov., 1675, and their canonization on 29 June, 1865. For many years the place of their martyrdom in Brielle has been the scene of numerous pilgrimagesand processions.