Orthodox Christianity first entered Lithuania in significant numbers in the 13th century with the conversion of some of its early nobles from paganism. Among these were the Three Martyrs of Vilnius,
Anthony, John, and Eustathius, martyred in 1347 under the Grand Duke
Algirdas. Formally established Orthodox parishes in Lithuania and in the surrounding region ultimately derive from the short-lived fourteenth-century
Metropolis of Lithuania and its successor jurisdictions (based largely in
Kyiv), which had been under the
Ecumenical Patriarchate of Constantinople. In the seventeenth century, the institutional presence of Orthodox Christianity was effectively erased from Lithuania as a result of the
Union of Brest, when Lithuania was part of the
Polish-Lithuanian Commonwealth. At that time, all the Orthodox parishes in Lithuania left the Orthodox Church and joined the Catholic Church. In the late 18th century, with the
Partitions of the Polish-Lithuanian Commonwealth, Lithuania became part of the
Russian Empire. The modern Russian Orthodox diocese was founded in 1839 with the incorporation of the
Uniate eparchy of Vilnius under Metropolitan
Joseph Semashko into the Russian church at the
Synod of Polotsk. Among the more notable hierarchs of Lithuania in the later imperial period was St.
Tikhon (Bellavin), who served in the post 1913–1917. The diocese functioned within the Russian empire until Lithuania
became independent in 1918. At that time, a number of the churches that had been taken from the Catholic Church were returned, and certain Orthodox churches, such as
Archangel Michael Church in Kaunas, were also given to the Catholic Church. Most of the Orthodox parishes that exist today in Lithuania were built during the imperial period (1795–1918). He was succeeded in 2010 by Metropolitan
Innocent (Vasilyev). == 2020s schism ==