Eastern Christianity took a firm root in Ukraine in 988 when Volodymyr, Prince of Kiev, embraced the Christian Faith and was baptized. Soon afterwards many missionaries from the Byzantine Empire arrived, having been sent by the Patriarch of Constantinople to preach the Gospel.
When the Church of Rome and the Church of Constantinople severed ties with one another in the 11th century, the Church in Ukraine gradually followed suit and finally gave up the bonds of unity with Rome. When Ukrainian Orthodox bishops met at a council in Brest-Litovsk in 1595, seven bishops decided to re-establish communion with Rome. Guaranteed that their Byzantine tradition and Liturgy would be respected and recognized by Rome, they and many priests and lay faithful were re-united with the See of Rome, while others continued to remain Orthodox.
The name Greek Catholic Church was introduced by the Empress Maria-Teresa in 1774 to distinguish this Church from the Roman Catholic and Armenian Catholic Churches.
In the 19th century many Ukrainian Catholics began to emigrate to North America, bringing their pastors, traditions and liturgy to United States and the Canada. Under Communist rule, Catholics in Ukraine were persecuted, with many being imprisoned and murdered; in 1945 all the Ukrainian Catholic bishops were arrested or killed.
In official church documents the term Ecclesia Ruthena unita was used. In 1960 the name Ukrainian Catholic Church (UCC) started to be used in official documents to refer to Ukrainian Catholics in the diaspora and the underground Church in Soviet Ukraine. In the papal statistical annual Annuario Pontificio the name Ukrainian Catholic Church of the Byzantine rite is used.
Today the Ukrainian Catholic Church is the largest Eastern Catholic Church sui juris, with about 5 million faithful. It is led by His Beatitude Patriarch Sviatoslav (Shevchuk). His election was confirmed by Pope Benedict XVI on 25 March 2011.