in the 11th century, and the new religion was beginning to organise and assert itself more effectively in Sweden. Foreign churchmen and native elites were energetic in furthering the interests of Christianity, which was now no longer operating only on a missionary footing, and old ideologies and lifestyles were transforming. By 1103, the first archbishopric was founded in Scandinavia, at Lund, Scania, then part of Denmark. The assimilation of the nascent Scandinavian kingdoms into the cultural mainstream of European Christendom altered the aspirations of Scandinavian rulers and of Scandinavians able to travel overseas, and changed their relations with their neighbours. One of the primary sources of profit for the Vikings had been slave-taking from other European peoples. The medieval Church held that Christians should not own fellow Christians as slaves, so chattel slavery diminished as a practice throughout northern Europe. This took much of the economic incentive out of raiding, though sporadic slaving activity continued into the 11th century. Scandinavian predation in Christian lands around the North and Irish Seas diminished markedly. The kings of Norway continued to assert power in parts of northern Britain and Ireland, and raids continued into the 12th century, but the military ambitions of Scandinavian rulers were now directed toward new paths. In 1107, Sigurd I of Norway sailed for the eastern Mediterranean with Norwegian crusaders to fight for the newly established Kingdom of Jerusalem; the kings of Denmark and Sweden participated actively in the Baltic Crusades of the 12th and 13th centuries. Culture A variety of sources illuminate the culture, activities, and beliefs of the Vikings. Although they were generally a non-literate culture that produced no literary legacy, they had an alphabet and described themselves and their world on runestones. Most contemporary literary and written sources on the Vikings come from other cultures that were in contact with them. Since the mid-20th century, archaeological findings have built a more complete and balanced picture of the lives of the Vikings. The archaeological record is particularly rich and varied, providing knowledge of their rural and urban settlement, crafts and production, ships and military equipment, trading networks, as well as their pagan and Christian religious artefacts and practices. Literature and language The most important primary sources on the Vikings are contemporary texts from Scandinavia and regions where the Vikings were active. Writing in Latin letters was introduced to Scandinavia with Christianity, so there are few native documentary