He had joined the Jesuits and was teaching Greek in Mechelen when in March 1679, while still a scholastic, he was called to Antwerp.
In 1670 John Ravesteyn had been assigned to assist Godfrey Henschen and Daniel van Papenbroeck in the compiling the lives of the saints, but left after five years to take up parish work.
Daniel Cardon took his place, but died in 1678 tending people stricken with the plague.
[1] Around 1695 his colleague Papenbroeck was under attack from the Spanish Inquisition and others opposed to the rigorous scholarly work of the Bollandists.
[2] Janninck also spent time in Austria and Hungary[3] as well as Italy[4] searching for relevant texts to aid in their efforts at recording the traditions regarding the early saints.