On September 14, 2026, Pope Leo XIV accepted the resignation of Archimandrite Jan Sergiusz Gajek, MIC, from his office as administrator of the Byzantine Rite Catholics in Belarus, due to Fr. Sergiusz reaching retirement age.
Archimandrite Jan Sergiusz Gajek was born in Poland, in Łyszkowice, in 1949. He belongs to the Congregation of the Marian Fathers of the Immaculate Conception of the Blessed Virgin Mary. He studied at the Catholic University of Lublin (KUL) and the Pontifical Oriental Institute in Rome. From 1983 to 1999, he taught the theology of the Eastern Churches at the Ecumenical Institute of the Catholic University of Lublin (KUL). In 1993, John Paul II appointed him Apostolic Visitor for the Greek Catholic faithful in Belarus. In 1996, he was elevated to the rank of Archimandrite. On March 30, 2023, Pope Francis elevated the structure of the Greek Catholic Church in Belarus to the rank of an Apostolic Administration and appointed Fr. Sergiusz as its first Administrator, though without conferring episcopal ordination upon him. The Byzantine Rite Catholic community in Belarus is the heir to the Union of Brest of 1596. It currently numbers about 5,000 faithful, organized into 16 parishes.
Archimandrite Jan Sergiusz Gajek, MIC, will be succeeded by the Studite Father Liavoncij Tumouski, who has until now been responsible for the pastoral care of Belarusian Greek Catholics in Poland.
Fr. Liavoncij (Aliaksandr) Tumouski, a Studite monk, was born on July 9, 1973, in Polotsk, in the Diocese of Vitebsk (Belarus). On May 27, 1995, he entered the Monastery of the Studite Monks at the Uniya Lavra in Ukraine. He studied philosophy and theology at the Major Seminary in Lviv and at the Ukrainian Catholic University in Lviv, earning a master’s degree in theology. From 2008 to 2018, he continued his studies in Rome, earning a licentiate and then a doctorate in theology at the Pontifical Oriental Institute. He was ordained a deacon in 2002 and a priest on May 18, 2003. He held the following positions: Superior of the Monastery of Saints Boris and Gleb in Polotsk, Belarus (2003–2008); Vicar of the Dean of the parish of the Belarusian Greek Catholic Church (2004–2006) and Dean of the Eastern Protopresbyterate (2006–2008); responsible for the pastoral care of the faithful of the Ukrainian Byzantine Rite in Greece (2015); he is currently responsible for the pastoral care of the faithful of the Belarusian Greek Catholic Church in Poland (since 2022).
