Johann Nikolaus von Hontheim (January 27, 1701 – September 2, 1790) was a German historian and theologian. He is remembered as Febronius, the pseudonym under which he wrote his 1763 treatise On the State of the Church and the Legitimate Power of the Roman Pontiff and which gave rise to febronianism.
Born in Trier, he belonged to a noble family which had been for many generations connected with the court and government of the Electors of Trier, his father, Kaspar von Hontheim, being receiver-general of the Electorate. At the age of twelve, young Hontheim was given by his maternal uncle, Hugo Frederick von Anethan, canon of the collegiate church of St Simeon (which at that time still occupied the Roman Porta Nigra at Trier), a prebend in his church, and on May 13, 1713, he received the tonsure. He was educated by the Jesuits at Trier and at the universities of Trier, Leuven, and Leiden, taking his degree of doctor of laws at Trier in 1724. The works of the Louvain professor Zeger Bernhard van Espen and his Gallican doctrine had a great influence on Hontheim.
During the following years he traveled in various European countries, spending some time at the German College in Rome; in 1728 he was ordained priest and, formally admitted to the chapter of St Simeon in 1732, he became a professor of the Pandects at the University of Trier.
In 1738 he was sent on official duty by the Elector to Coblenz, where he discharged the duties of official and president of the Grand Séminaire of that city. In that capacity, he had plenty of opportunities to study the effect of the influence of the Roman Curia in the internal affairs of the Empire, notably in the negotiations that preceded the elections of the emperors Charles VII and Francis I in which Hontheim took part as assistant to the electoral ambassador. It appears that it was the claims of the papal nuncio on these occasions and his interference in the affairs of the electoral college that first suggested to Hontheim that critical examination of the basis of the papal involvement, the results of which he afterwards published to the world under the pseudonym of Febronius.