Religion was an important aspect of Polabian society. Much of their territory was dotted with holy places in nature to which the Slavs could pray and make offerings to Slavic gods. The priesthood was an important class which developed images and objects of worship. Polabian towns often included elaborate temples often visited for offerings and pilgrimages. In contrast, priests in the countryside often lived meagerly. History The Polabian Slavs replaced the Germanic tribes who had emigrated from the 1st to 6th centuries during the Migration Period. Their settlement area was largely stable by the 8th century. Charlemagne enlisted the Obotrites as allies in his campaign against the rebellious Saxons of Holstein. Many of the Slavic tribes became dependencies of the Carolingian Empire and the Franks created the Sorbian March to defend against the Sorbs. Einhard in Vita Karoli Magni describes an expedition into Slavic territory led by Charlemagne himself, in 798. The Veleti noted as Wilzi (referred to themselves as Welatabians) were invaded by the Franks because of their continuous expeditions into Obodrite lands, with the Obodrites being allies of the Franks against the Saxons. German campaigns against the Slavs began in earnest during the Ottonian dynasty. Henry the Fowler attacked the Slavs in several campaigns with his cavalry. During the reigns of Henry and his son Otto I, several marches were established to guard the eastern acquisitions, such as the Billung March to the north and the Marca Geronis to the south. After Gero's death in 965, the Marca Geronis was divided into the Northern March, the March of Lusatia, and the Thuringian March, the latter being divided into the marches of Zeitz, Merseburg, and Meissen. Bishoprics such as Magdeburg, Brandenburg, and Havelberg were founded to support the conversion of the Slavs to Christianity. After the defeat of Otto II at the Battle of Stilo in 982, the pagan Slavs rebelled against the Germans the following year; the Hevelli and Liutizi destroyed the Bishoprics of Havelberg and Brandenburg, and Obotrites (Mstivoj) destroyed Hamburg. Some Slavs advanced across the Elbe into Saxon territory, but retreated when the Christian Duke of Poland, Mieszko I, attacked them from the east. The Holy Roman Empire retained only nominal control over the Slavic territories between the Elbe and the Oder. Despite the efforts of Christian missionaries, most Polabian Slavs saw Jesus as a "German god" and remained pagan. The Obotrite prince Udo and his