The Archdiocese owes its foundation to Jogaila, who Christened Lithuania in 1387 and sent Dobrogost, Bishop of Poznań as ambassador to the Pope Urban VI with a petition for the erection of an episcopal see at Vilnius and the appointment of Andrzej Wasilko (former bishop of Siret and confessor of Elisabeth of Hungary) to fill it. This was granted and the foundation of a collegiate church of ten canons authorized. Under Wasilko's rule, the churches of Saint John, that became the parish church of the city, as well as of Saint Martin and Saint Anne (in the Upper and the Lower Castle, respectively) were erected in Vilnius. Upon Wasilko's death in 1398, he was succeeded by a Franciscan, Jakub Plichta (1398–1407), in whose time the Cathedral perished in fire. Among his successors were: Piotr Krakowczyk of Kustynia (1414–1421), whom Pope Martin V invested with full powers to bring back the Orthodox of Lithuania to the Catholic Church; Matthias of Trakai (1421–1453), a Lithuanian, who sent representatives to the Council of Basel and set up the Inquisition to combat the Hussites, founded many churches and strenuously defended the rights and privileges of the Lithuanians. Under Jan Łosowicz (1467–1481) many Ruthenians were converted to Catholicism and the Franciscan Bernardines were established at Vilnius. Albert Tabor, a Lithuanian, invited the Dominicans to Vilnius and entrusted to them the Church of the Holy Spirit; Albert Radziwiłł (1508–1519) died in the odour of sanctity; John the Lithuanian (1519–1537) held the first diocesan synod at Vilnius in 1526; Prince Paweł Holszański (1534–1555) restored his cathedral in the Gothic style and held a synod in 1555; Walerian Protasewicz Suszkowski (1556–1580) had to contend for the celibacy of the clergy and the use of Latin in the Liturgy; he brought the Jesuits, among whom was Piotr Skarga, to Vilnius.