Atanas Sielava was born on about 1583 in the Polotsk Voivodeship from a family of Cossack origin and belonging to the Orthodox religion. In 1612 he entered in the Order of Saint Basil the Great, in the monastery of the Holy Trinity in Vilnius, taking the religious name of Anton. He lived for some time in the same cell with Saint Josaphat Kuntsevich and he was ordained a priest in 1617. He studied in the Greek College in Rome from 1617 to September 1619. On 12 November 1623 the bishop of Polotsk, Josaphat Kuntsevich, was killed by an Orthodox mob. After him, Anton Sielava was appointed to the See of Polotsk. He was consecrated a bishop in early 1624 by Metropolitan Joseph Rutski and enthroned on 14 February 1624. To Metropolitan Joseph Rutski succeeded Metropolitan Rafajil Korsak, who, when in 1639 left Belarusto go to Rome for Visit ad Limina, appointed Sielava as Vicarius for the Church. Rafajil Korsak died in Rome in August 1640 and, according to his last will, Pope Urban VIII confirmed Sielava as new Metropolitan after the usual process of eligibility. Anton Sielava was so formally appointed Metropolitan of Kiev on 18 March 1641. His patriarchate was initially marked by the beatification, on 16 May 1643, of Josaphat Kuntsevich. Following his predecessors Joseph Rutski and Rafajil Korsak, Sielava went on in negotiations with the Orthodox Patriarch of Kiev, Peter Mogila about the way to unify the Ukrainian Church. However he was not a person of the stamp of his predecessors, and after the death of Mogila, the discussions ended without results. Sielava left much part of the administration of the Church to others, and he was of a sickly disposition and quite hypochondriac, and in the last part of his life he was seriously ill and blind. Since 1648, the political situation in the Polish–Lithuanian Commonwealth underwent years of crisis due to the Khmelnytsky Uprising, a Cossack rebellion in Ukraine fiercely anti-Catholic, followed by the Russo-Polish War and Second Northern War. The Greek-Catholic Church was seriously threaten, many churches, monasteries and schools were destroyed, and priests and monks killed. Sielava had to leave Polotsk and died on 5 October 1655, when already the Greek-Catholic Church was in the resolute hands of Gabriel Kolenda.
Works
Anton Sielava was also a writer and a polemist. Among his works we have his "Antelenchus", against the "Elenchum" of Meletius Smotrytski, and his "Vitam Servi Dei Josaphat, Archiepiscopi Polocensis" edited in 1624.
