Education
University of Paris.
University of Paris.
He was ordained priest in 1648 and in 1652 joined the Dutch Mission. In 1662 he was consecrated titular bishop of Castorie and in 1663 made vicar apostolic. In that role he maintained good relations with the civil authorities of the Dutch Republic, winning some degree of tolerance for Catholics.
After the capture of Utrecht by the French in 1672, the French authorised Catholics to worship publicly - the Cathedral was returned to Catholic use and Van Neercassel celebrated Mass there many times.
On 22 August 1673 he even organised a major procession of the Holy Sacrament through the city streets. He hoped to re-establish Utrecht as an episcopal seat, but Rome showed much hesitation on the issue, the Holy See being unfavourable to the seat being restored under French protection.
The liberties Catholics had gained came to an end in 1673, when the French were forced to retreat from Utrecht. He later died of complications from pneumonia.
A respected figure on the international stage, with an excellent network of contacts in France and Rome, Johannes van Neercassel represented spiritualist Jansenism and had good relations with Portuguese-Royal.
In time the Jesuits succeeded in undermining his position and his theological work Amor poenitens (1683) was put on the Index of Prohibited Books after his death.