The first historical Christian communities in the Ukrainian Crimea were founded at the end of the 1st century by Pope Clement I, who was in exile there.

In the third and fourth centuries, there was a Gothic bishopric in the south of Ukraine, whose representatives took part in the First Council of Nicaea.

There is reason to believe that the prince received his name in honor of Pope Nicholas I, who pursued an active policy in the baptism of the Slavs and blessed the translations of the Bible made by Cyril and Methodius in the Slavic languages.

By the middle of the 10th century, during the reign of Prince Igor, the Christian community had grown and churches were being built.

He died in 961, and in the same year a German-Latin mission led by Bishop St. Adalbert of the Trier Monastery arrived in Kiev.

This is evidenced by the embassies from Rome, which brought the relics of Saints Clement and Titus to Korsun to Prince Vladimir in 988.

In addition to ecclesiastical and political ties with the Holy See and the West, there were also dynastic ones, founded by Vladimir and inherited by his successors, including Yaroslav the Wise, whose four daughters married Christian kings of Norway, Hungary, France and Germany.

The death of Prince Yaroslav the Wise and the gradual fragmentation of the Kyivan state affected the situation of the western Ukrainian lands.

In 1207, Pope Innocent III, through Cardinal Gregory, offered the Galician-Volyn state close contacts, trying to unite the peoples of Eastern Europe with Rome.

After the Tatar invasion, which began in 1239, the West united an anti-Tatar coalition, where it assigned a special role to Ukraine, and in particular to Prince Danylo Halytsky.

But three years later, in 1256, at the request of the Tatars, Daniel severed ties with Rome, and the Pope transferred the Catholics who lived in Red Rus to the jurisdiction of the Bishop of Lublin, who had a vicar general in Volodymyr.

Pope Gregory XI, with the bull "Debitum pastoralis offici" of 13 February 1375, finally founded the Latin metropolitanate and archdiocese with its seat in Galicia.

Due to the greater distance from the Tatars in 1412, its settlement was moved from Halych to Lviv (bull "In eminenti specula" of 28 August 1412).

After him, three other archbishops were Galician metropolitans: Bernard (1384-1390), c. Jakub Strzeme (Strepa) (1391–1409), beatified in 1790, and Mykolay Tromba (1410–1412).

The Kyiv Orthodox Metropolitanate gradually embraced all East Slavic lands, bringing them into the ecclesiastical orbit of Byzantium.

Geographical location led to contacts through trade, military action and diplomatic relations with the Eurasian steppe, the Baltic North, the Catholic West.

Archbishop Peter Akerovich together with Pope Innocent IV conducted the Divine Liturgy in Lyon.

Metropolitan of Kyiv Hryhoriy Tsamblak, not recognized as the Patriarch of Constantinople, took part in the cathedral in Constanta with a delegation of 300 people.

Pope Pius II proclaimed the Greek Gregory archbishop of Kyiv, Lviv and all of Little Rus.

The papal bull also testified that Rome had no illusions about the prospects of the Florentine union in Greater Rus under the schismatic rule of Jonah of Moscow.

From 1458 to 1596 (Brest Cathedral) the lands of the Kyivan metropolitanate coincided with the borders of the dynastic United States - Poland and Lithuania.

On the Latin side, the idea of union was supported by the Jesuits Peter Skarga, Antonio Possevino, and the Apostolic Nuncio.

The idea of uniting the churches of the two rites gave an example of asceticism - the life and martyrdom of Polotsk Archbishop Josaphat Kuntsevich, killed in 1623 by fanatics in Vitebsk.

His relics in 1916 were found in the Kholm region and brought to Vienna, where they remained until 1944 in the church of St. Barbarians, and then transported to Rome to the Cathedral of St. Petra.

The vast majority of religious structures of the RCC operate in the west of the country, in particular in Lviv (163), Khmelnytsky (153), Zhytomyr (145), Vinnytsia (131), Zakarpattia (100), Ternopil (91), Ivano-Frankivsk (37) regions.