Fearing the scenario of a joint German-Danish attack, in 1028 Mieszko took the initiative and invaded Lusatia in the eastern Empire and occupied the territories of the Lutician Federation, where West Slavic Polabian tribes had settled and represented the majority of the population since the 10th century after centuries of steady immigration. Slavs had long been the target of imperial military campaigns, particularly for the punishment and subjugation of pagan tribes. During the early years of the Ottonian dynasty Emperor Otto I's lieutenants Herman Billung and Gero, subdued and harassed Slavic settlers beginning in the 940s. In 983, as part of the Slavic revolt of 983, the Lutici rose in an open rebellion. In the ensuing war (983-995), the Lutici succeeded in reclaiming their independence and gained control of the Billung March and Northern March from the Empire. Though Emperor Otto III allied with Duke Bolesław I of Poland to reintegrate them into the Empire, Otto III's death ended the friendly relationship between Poland and the Empire. Instead, Bolesław competed with Otto III's successor, Emperor Henry II, for dominion over the Lutici, causing Henry II to ally the Empire with the Lutici against Poland. Under the Peace of Bautzen in 1018, all three parties remained in uneasy peace, with Poland allowed to hold the Empire's Margraviate of Meissen. Of the eastern marches, the Empire only retained the March of Lusatia. Mieszko's 1028 invasion ended the peace. The Lutici sent ambassadors to seek Conrad's protection against Mieszko, which Conrad granted and renewed the German-Lutician alliance.