In the Low Countries, then under the rule of Spain, Emperor Charles V and his son King Philip II instituted a systematic campaign to root out the new religious movements, which resulted in political resentment towards the authorities, including the Catholic Church.

[2] By 1572 the Netherlands were in open revolt against Spanish rule, while in the internal rivalry among the Protestant denominations, Calvinism managed to suppress Lutheranism.

On 1 April of the next year, Calvinist forces and a rebel group called the Watergeuzen (Sea Beggars) captured Brielle (Den Briel) and later Vlissingen (Flushing).

[3] In June, Dordrecht and Gorkum fell, and at the latter the rebels captured nine Franciscan priests: Nicholas Pieck, guardian of Gorkum; Hieronymus 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 Franciscus de Roye of Brussels.

To these fifteen were later added four more companions: Joannes van Hoornaer (alias known as John of Cologne), 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 became a curate in Monster, South Holland; Adrianus Janssen of Hilvarenbeek, a Premonstratensian canon and at one time parish priest in Monster, who was sent to Brielle with Jacobus Lacops.