One of the most important concerns of Bolesław's early reign was building up the Polish church. Bolesław cultivated Adalbert of Prague of the Slavník family, a well-connected Czech bishop in exile and missionary who was killed in 997 while on a mission in Prussia. Bolesław skillfully took advantage of his death: his martyrdom led to his elevation as patron saint of Poland and resulted in the creation of an independent Polish province of the Church with Radim Gaudentius as Archbishop of Gniezno. In the year 1000, the young Emperor Otto III came as a pilgrim to visit St. Adalbert's grave and lent his support to Bolesław during the Congress of Gniezno; the Gniezno Archdiocese and several subordinate dioceses were established on this occasion. The Polish ecclesiastical province effectively served as an essential anchor and an institution to fall back on for the Piast state, helping it to survive in the troubled centuries ahead.