Parczewski was born in an Orthodox family. After the adoption of Catholicism, he entered in the seminary of
Vilnius and was later sent to the Papal Seminary in
Braniewo. He continued his studies at the
Vilnius University where he received the master's degree in philosophy in 1622. Later, Parczewski earned a doctorate in theology and was ordained to the priesthood in 1628, became rector in
Starodub. In 1630, became the administrator of the Diocese of Smolensk. During the
Smolensk War in 1632–1634, he remained besieged in Smolensk. In 1635, King
Wladyslaw IV Vasa appointed him as the first bishop of Smolensk, and then Parczewski went to Rome to obtain the approval of the new diocese, which was received on September 1, 1636. On September 7 of the same year, he was ordained a bishop by Cardinal
Giovanni Battista Pamphili (future
Pope Innocent X). At the end of 1649, Parczewski became bishop of Samogitia. In 1651, carried out a visitation of the diocese. During the
Swedish Deluge, on 18 August 1655, he signed the
Treaty of Kėdainiai, an instrument of surrender to
Charles X Gustav of Sweden. On October 20 of that year, he signed the
Union of Kėdainiai which established the Swedish–Lithuanian union. Parczewski died on 6 December 1658. ==Sources==