The Eparchy of Križevci is the eparchy comprising the Croatian Byzantine Catholic Church, a Catholic Church sui iuris  of the Byzantine Eastern Rite. It spans the former Yugoslav republics of Croatia, Macedonia, and Bosnia; it gathers Serbs faithful in Croatia (mostly Žumberak) and Macedonian Slavs in FYR Macedonia as well as some Rusyns or Ukrainians in Slavonia and Northern Bosnia. The liturgy in the Slavonic Rite uses the Old Church Slavonic language and the Cyrillic alphabet.
Formation of the Eparchy of Križevci
Croatia, Slavonia and Bosnia saw much turmoil from 1414 to 1838 owing to wars with Venice and the invading Turks.  The arrival of Christian refugees, mostly Orthodox Serbs and Vlachs, in the Military Frontier from the Turkish invasions of the 16th and 17th centuries is related to the establishment of a Byzantine Rite church in this part of the Hungarian kingdom. In 1611 the Serbs were accorded a bishop to served as Byzantine vicar of the Latin Bishop of Zagreb. The Byzantine vicar was based in Marča Monastery which would later become a center of efforts for Rome's attempt to bring the Serbian Orthodox faithful under its jurisdiction. The Križevci eparchy was finally erected in 1777 after a long bout with the Serb Orthodox clergy.
In 1646 some Byzantine priests from the Mukacevo eparchy and several other locations returned to full communion with the Bishop of Rome. The Union of Uzhorod, as it is called, has its origins in the Council of Florence (1439) plan to bridge the Schism and encourage full communion of Eastern Orthodoxy with the Holy See, and eventually led to the foundation of the eparchies of Križevci (Pope Pius VI on June 17, 1777), Presov (1818), and Hajdudorog (1920).  The Orthodox Serbs resisted, particularly in the metropolitan of Karlovci, Arsenije III Čarnojević . However a regiment of Serbs of the Žumberak regiment of the Military Frontier accepted. Križevci, the location of the see, is a town northwest of Zagreb. The new bishop was initially suffragan to the Primate of Hungary, and later (1853) to the Latin Archbishop of Zagreb.
Križevci was expanded after World War I to include all Byzantine Catholics in the former Yugoslavia. Owing to this expansion and to population movements over time, Križevci includes Catholics of varied national heritage  including ethnic Serbs from Žumberak, Rusyns in Slavonia and Serbia who had emigrated from Carpatho-Ukraine and Slovakia around 1750, Ukrainians who emigrated from Galicia (now in Ukraine) around 1900, Macedonian Slav converts from missionary activity in the 19th century as well as a few Romanians in the Serbian part of the Banat (Vojvodina). Today the eparchy includes between 50,000  and 77,000  Byzantine Catholics. However the last census in the Republic of Croatia, in 2001, listed only 6219 Greek-Catholics. This is owing to the fact that many have converted to Roman Catholicism outright. This might explain complaints by some Serb Greek Catholics that they were christened according to the Latin Rite against their will or knowledge.
The first Byzantine Catholic priest from Croatia came to the United States of America in 1902, whose work in Cleveland was encouraged by the bishop of Križevci.  Another Croatian priest came to Allegheny, Pennsylvania, in 1894.  Križevci is one of the four Eastern European eparchies that are the roots of the Eastern-rite Catholic Churches in the United States. 
"During World War II, the Slovak State suspected the [Greek Catholic] Redemptorists of anti-State propaganda since they were helping Ruthenians in a Slovak nationalist situation."  "Methodius Dominic Trcka, ... superior of the Redemptorist community in ... Eastern Slovakia, [was active] in the three Eparchies of Presov, Uzhorod and Križevci. With the arrival of the Communist regime, he was deported to a concentration camp with his Redemptorist colleagues." 
The eparchy of Križevci is currently headed by Bishop Slavomir Miklovš, a Ruthene (born 1934, appointed 1983). Note that not all Catholic bishops in Croatia are Eastern-rite Catholics. In 2002 a separate Apostolic Exarchate was created for Greek Catholics in Serbia and Montenegro  after the formation of independent republics from what had been Yugoslavia. Almost all of the Greek Catholics in Serbia are some 18,000 Rusyns and Ukrainians (in the Backa), 4,000 Slovaks also in the Backa and 2,000 Romanians in the Serbian Banat.