 The cathedral was built during the reign of the Grand Duke of Lithuania Algirdas for his Orthodox second wife Uliana of Tver in 1346.It was constructed by Kievan architects with the blessing of Saint Alexius, Metropolitan of Kiev and all Rus', in 1348.The Cathedral of the Theotokos is one of the most ancient churches of Vilnius, built before the christianization of Lithuania when the Grand Duchy of Lithuania was the last pagan state in Europe.