Due to their geographical location, Lithuanians, while still followers of the pagan religion, often came into contact with the Orthodox Church[3]. Many Lithuanian warriors and princes acquired estates in the Ruthenian lands, often being baptized in the rite of this denomination[3]. Orthodox churches, and possibly also monasteries, in Vilnius were founded by Julianna Twerska – the second wife of Grand Duke Olgierd. Apart from the founder and her entourage, the temples were also used by Russian merchants[3], who in the first half of In the 14th century, they already formed a compact colony in the city[4]. As a result of the territorial development of the Grand Duchy of Lithuania in the 13th and 14th centuries, the number of Orthodox Ruthenians living within its borders increased[5]. The Orthodox adopted three Trojdena brothers, Wojsiełk, sons of Giedymin Jawnut (Iwan), Narimunt (Gleb), Lubart (Dymitr)[3].
The Orthodox clergy of the Kiev metropolis were loyal to the secular rulers of Lithuania. From the end of the 13th century, throughout the 14th century, the rulers of Lithuania sought to separate the Kiev metropolis into a separate Lithuanian metropolis, due to the fact that the growing Muscovite state tried to spread anti-Lithuanian propaganda among the Orthodox inhabitants of Lithuania[b]. In 1299, the establishment of the Lithuanian metropolis with its seat in ########## was approved by the Patriarch of Constantinople, John XII, positively responding to the efforts of Witenes. The Lithuanian metropolitan held the 82nd position in the hierarchy of the Patriarchate of Constantinople. The agreement to establish a new administration resulted from the policy of the Byzantine emperor Andronicus II, who was reluctant to the Latin Church and sought to strengthen the position of the Orthodox Church in Slavic countries[5]. The actual beginning of the activity of the Lithuanian metropolis took place in 1315[6], the name of the first superior is unknown. Information about the structure of the Lithuanian metropolis and its possible eparchies have not survived either. The metropolitan himself was unable to carry out extensive missionary work due to the lack of support from pagan princes and the activity of Roman Catholic orders[5]. In 1330, the Lithuanian metropolis was liquidated. The likely initiator of this move was the Metropolitan of Kiev, Theognost, who sought to reunite all Orthodox structures in the East Slavic lands in one metropolis of Kiev[8].
In 1327, Grand Duke Olgierd, after marrying Anna Maria, Duchess of Vitebsk, baptized his four eldest sons in the Orthodox rite and considered introducing Christianity to Lithuania[9]. In 1354, Olgierd resumed his efforts to reactivate the Lithuanian metropolis and demanded that the Ruthenian Orthodox eparchies be subordinated to it. These activities were successful and in 1354 Bishop Theodorite became the head of the renewed metropolis[10]. In the same year, he was replaced by Bishop Roman, Olgierd’s brother-in-law. He immediately found himself in conflict with the Metropolitan of Kiev, Alexei, residing in Moscow, who did not accept the exclusion of the Lithuanian metropolis from his jurisdiction. In 1355 this question was discussed at the patriarchal synod in Constantinople. In the following year, he finally resolved the issue of the administrative division of the Church in the Lithuanian and Ruthenian lands, subordinating the ########### Bryansk and Polotsk eparchies to the Lithuanian metropolitans[11]. Metropolitan Roman, however, continued to try to take over the office of the Metropolitan of Kiev. The dispute between the hierarchs, which made it difficult for metropolises to carry out missionary activities, discouraged Olgierd from baptizing Lithuania in the Orthodox rite[11]. In 1362, after Lithuania seized the land of Kiev, Roman moved his residence to Kiev[11]. Although during Olgierd’s reign there was a significant development of the Orthodox Church in Lithuania, it did not become the dominant denomination[11]. According to Antoni Mironowicz, the reason for this was the fear of Muscovite influences that could spread through religion in the Lithuanian provinces[11]. At the same time, the pagan Grand Duchy of Lithuania was tolerant of both Eastern and Western Christians[12].
In 1361, the patriarchal synod in Constantinople again discussed the issue of the border between the Lithuanian and Kiev metropolises. The first included the eparchies of Polotsk and Turów, but the jurisdiction of the five eparchies in Volhynia was not unequivocally resolved. ########## remained the seat of the metropolitan. The most important centers of Orthodox religious life were the cities-seat of bishops and Vilnius[11]. In 1390, there were eleven Orthodox churches and the Holy Trinity Monastery in the city, along with seven Catholic churches and a Bernardine monastery[13]. Monasteries played a special role[11]. In the Grand Duchy of Lithuania, 90% of the population professed Orthodoxy (they were Ruthenians and Lithuanians who underwent Ruthenianization; this process was visible among the country’s elite). The country was dominated by Ruthenian culture[14]. However, in 1362, after the death of Metropolitan Roman, the Patriarch of Constantinople did not appoint his successor. Formally not being dissolved, the Lithuanian metropolis had no superior until 1377. In 1375, Grand Duke Olgierd demanded that the Patriarch of Constantinople remove the lands of the Grand Duchy of Lithuania from the jurisdiction of Alexius, Metropolitan of Kiev, threatening delegalization of the Orthodox Church in his country in case of refusal. A candidate, supported by Olgierd at that time, was sent to Lithuanian lands – the Bulgarian Bishop Cyprian, who combined the administration of the Lithuanian and Halych metropolises[15].
In 1383, the Grand Duke of Lithuania Jagiełło started talks with Moscow regarding a possible alliance, which would be associated with the acceptance of baptism by Lithuania in the Orthodox rite. However, bearing in mind the possible loss of Lithuanian Ruthenian lands, he abandoned this project in favor of talks with Poland about a possible union[16]. Jogaila also took into account the fact that the adoption of Orthodoxy by Lithuania would not stop the aggression of the Teutonic Knights, because Eastern Christians were considered heretics by the Latin West[17].