in order to Christianize the Polabian Slavs but it had been effectively destroyed in 983 with the Great Slav Rising following the death of Otto II that year. Otto III arranged for his imperial palace to be built on the Palatine Hill and planned to restore the ancient Roman Senate to its position of prominence. He revived the city's ancient governmental system, including appointing a City Patrician, a City Prefect, and a body of judges whom he commanded to recognize only Roman law. In order to strengthen his title to the Roman Empire and to announce his position as the protector of Christendom, Otto III took for himself the titles "the Servant of Jesus Christ," "the Servant of the Apostles", "Consul of the Senate and People of Rome," and "Emperor of the World". Between 998 and 1000, Otto III made several pilgrimages. In 999, he made a pilgrimage from Gargano to Benevento, where he met with the hermit monk Romuald and the Abbot Nilus the Younger (at that time a highly venerated religious figure) in order to atone for executing Crescentius II after promising his safety. During this particular pilgrimage, his cousin Pope Gregory V died in Rome after a brief illness. Upon learning of Gregory V's death, Otto III installed his long-time tutor Gerbert of Aurillac as Pope Sylvester II. The use of this papal name was not without cause: it recalled the first pope of this name, who had allegedly created the "Christian Empire" together with Emperor Constantine the Great. This was part of Otto III's campaign to further link himself with both the Roman Empire and the Church. Like his grandfather before him, Otto III strongly aspired to be the successor of Charlemagne. In 1000, he visited Charlemagne's tomb in Aachen, removing relics from it and transporting them to Rome. Otto III also carried back parts of the body of Bishop Adalbert of Prague, which he placed in the church of San Bartolomeo all'Isola he had built on the Tiber Island in Rome. Otto III also added the skin of Saint Bartholomew to the relics housed there. Affairs in Eastern Europe Polish relations Around 960, the Polish Piast dynasty under Mieszko I had extended the Duchy of Poland beyond the Oder River in an effort to conquer the Polabian Slavs, who lived along the Elbe River. This brought the Polans into Germany's sphere of influence and into