Congress of Gniezno

The Congress of Gniezno (Zjazd gnieźnieński, Akt von Gnesen or Gnesener Übereinkunft) was an amicable meeting between the Polish Duke Bolesław I the Brave and Emperor Otto III, which took place at Gniezno in Poland on 11 March 1000. Scholars disagree over the details of the decisions made at the convention, especially whether the ruler of Poland was pledged the king's crown or not. After his death in 997 during a mission among the pagan Prussian tribes, Bishop Adalbert of Prague was quickly canonized by the common effort of Duke Bolesław I and Emperor Otto III. Thus, Adalbert became the first Slavic bishop to become a saint. His body, bought back by Bolesław from the Prussians for its weight in gold, was put into a tomb at Gniezno Cathedral, which became the ecclesiastical center of Poland. According to the chronicles of Thietmar of Merseburg, Otto III, who had been a friend and pupil of Adalbert, committed to a from Italy to St. Adalbert's tomb in Gniezno; in his attempt to extend the influence of Christianity in Central and Eastern Europe, and to renew the Holy Roman Empire based on a federal concept ("renovatio Imperii Romanorum") with the Polish and Hungarian duchies upgraded to eastern federati of the empire. As part of this policy he also invested Grand Prince Stephen I of Hungary with the king's crown (the Crown of Saint Stephen). The Polish Piast dynasty under Mieszko I had extended their domains beyond the Oder river, where their claims to power collided with the interests of the Saxon margrave Gero. After his defeat by Gero's troops in 963, Mieszko I decided to come to terms with Emperor Otto I and agreed to pay tribute for this part of his lands. In turn he gained the title of amicus imperatoris ("Friend of the Emperor") and the acknowledgment of his position as a Dux of Poland. He continued his policy of convergence with the Empire by marrying Oda, the daughter of the Saxon margrave Dietrich of Haldensleben, in 978 and by marrying his son Bolesław I to a daughter of Margrave Rikdag of Meissen.