The Catholic clergy of the Habsburg Realms experienced several disruptive events from the 1750s. During the reign of Maria Theresa (1740-1780) and Joseph II (1780-1790) more and more radical ecclesiastical policies led to the confiscation of church properties: approximately one third of the monasteries were dissolved and the remaining houses were subject to strong governmental control. Episcopal power became also strongly limited and the bishops were forced to take a newly introduced oath of allegiance before they were installed into their episcopal estates. The Napoleonic invasion of the Habsburg territories resulted in a new wave of monastery dissolutions in the Austrian and Lombard territories, several prince bishoprics of the German territories were merged into newly created political entities and the existence of the Holy Roman Empire formally ended in 1806. The revolutions following the Congress of Vienna continued to create tensions regarding the position of the Catholic Church and called into question the legitimacy of the legal frameworks that secured its wealth in the individual countries. These disruptions experienced in the past and feared to reoccur in the future probably contributed to the appeal of the Belgian banker, André Langrand-Dumonceau (1826–1900), whose widespread entrepreneurial and financial activities aimed to serve the purpose of creating a “Catholic financial empire”. Dumonceau relied on several agents and intermediaries, among whom the Hungarian titular bishop of Pristina, János Danielik, deserves special attention. Danielik was a mediator in various contexts around 1764: he is considered as the initiator of secret negotiations that led to the Austrian-Hungarian compromise in 1867 and it is assumed that he arranged a credit for the Papal States provided by Dumonceau and the financial aid obtained this way supported the military defense of the Papal States against the Royal Italian Army. The negotiations preparing the Austro-Hungarian Compromise and the process of the Italian Unification destabilized the position of the Catholic clergy and papal power both in Hungary and in the Italian peninsula. Danielik suggested a surprising solution to safeguard the wealth of the church: he clandestinely recruited Hungarian bishops to sell episcopal estates to Dumonceau’s bank. Nevertheless, these plans were never realized: the scandalous bankruptcy of the Belgian banking house and the disclosure of Danielik’s plans in a series of journal articles prevented further actions. The attempt to prevent a new wave of sequestrations of church property by using the protection of private property granted to foreign entrepreneurs and financiers deserves attention as a way of warding off potential new disruptions in the operation of the Catholic church. This paper investigates Danielik’s role by bringing together so-far disjoined results of studies published in French, Italian, Hungarian and German.