Bishop Josip Juraj Strossmayer, in spite of the surname he inherited from his German great-grandfather, was a hero of Croatian nationalism. Born in Osijek, in Croatia’s eastern province of Slavonia, he studied for the priesthood in the nearby city of Đakovo and later in Vienna, where his brilliance gained him attention, and he was appointed a court chaplain. Under the sponsorship of Emperor Franz Joseph I, Strossmayer was made bishop of Đakovo in 1850, at the age of 35.

Josip Juraj Strossmayer, 1815–1905
His prosperous diocese provided the bishop with a large income, much of which was spent in causes devoted to the promotion of Croatian culture and national identity. Noted as a scholar and esthete, Bishop Strossmayer also spent generously on the building and renovation of churches. He was a principal founder of the University of Zagreb, the first university in the Balkan lands, and helped form a nationalist political party to resist the Magyarization that Hungary kept trying to impose on Croatia throughout the 19th century.

For all his nationalist sentiment, Bishop Strossmayer advocated loyalty to the Habsburg Monarchy. But he believed, like many others, that it should become a “Triune Kingdom” of Germans, Hungarians, and Slavs, not merely a partnership of the first two peoples (who were collectively outnumbered by the Empire’s large Slavic population). This hope was never realized, however; neither Austrians nor Hungarians were inclined to surrender any of their power.

As for the Serbs living in Croatia, Strossmayer felt that they should, over time, merge with the majority and become Croats. His party objected to their forming national organizations of their own within Croatia. But he was sympathetic to the Serbian Kingdom, to which the Vatican appointed him Papal Nuncio, and on the Pope’s behalf he negotiated a concordat with Montenegro, another independent kingdom of Orthodox Christian Serbs. As a Catholic bishop, he may have entertained the hope that the Orthodox Christians would someday come into the Roman fold, but he apparently understood that such a thing could happen only in the fullness of time. Strossmayer would have been appalled by the attempts of some later Croatian rightists to force Serbs into the Catholic Church at gunpoint.

At the First Vatican Council, in 1870, Bishop Strossmayer was among the leading opponents of the motion to proclaim the doctrine of papal infallibility, but he wound up on the losing side of that struggle.