Nelis was born in
Mechelen on 5 June 1736, the son of Cornelis Nelis, advocate of the
Great Council of Mechelen. He was educated at the
Oratorian College in Mechelen and at the
University of Leuven, where he graduated
Bachelor of Arts as the first of his year on 27 October 1753. He pursued further studies in theology, graduating
Licentiate in Theology on 6 May 1760. In the meantime, he had been appointed director of Leuven University's
Mechlin College in 1757 and university librarian in 1758. He played an important role in the creation of Leuven's University Press in 1759. He was nominated as bishop of Antwerp on 15 February 1785, his appointment was confirmed by
Pope Pius VI on 25 April, and he was
consecrated on 5 June. Although initially a supporter of
Emperor Joseph II's reform programme, he gradually came under suspicion of inspiring resistance to radical change, and on 26 October 1788 his arrest was ordered and he went into hiding. After the creation of the
United States of Belgium in January 1790, Nelis was appointed president of the States General. He worked hard to maintain agreement between the provinces adhering to the union. After the collapse of the union in December 1790, he eventually came to support the claim of
Francis II, Holy Roman Emperor, to rule in the Low Countries. During the
French Revolutionary War in the Low Countries Nelis sought refuge first in the Netherlands and then in Germany, eventually making his way to Italy in 1795. He died at the
Camaldolese religious community in Florence on 21 August 1798. After his death his library was auctioned off in the Low Countries, with many of the items of historical value being bought by
Charles van Hulthem, whose collection was an important acquisition of the later
Royal Library of Belgium. ==Publications==