a severe blow when the Western Roman Empire fell in the 5th century. The expansion of Islam in the 7th century had also affected trade with western Europe. Raids in Europe, including raids and settlements from Scandinavia, were not unprecedented and had occurred long before the Vikings arrived. The Jutes invaded the British Isles three centuries earlier, pouring out from Jutland during the Age of Migrations, before the Danes settled there. The Saxons and the Angles did the same, embarking from mainland Europe. The Viking raids were, however, the first to be documented in writing by eyewitnesses, and they were much larger in scale and frequency than in previous times. Vikings themselves were expanding; although their motives are unclear, historians believe that scarce resources or a lack of mating opportunities were a factor. The "Highway of Slaves" was a term for a route that the Vikings found to have a direct pathway from Scandinavia to Constantinople and Baghdad while traveling on the Baltic Sea. With the advancements of their ships during the 9th century, the Vikings were able to sail to Kievan Rus and some northern parts of Europe. Jomsborg Jomsborg was a semi-legendary Viking stronghold at the southern coast of the Baltic Sea (medieval Wendland, modern Pomerania), that existed between the 960s and 1043. Its inhabitants were known as Jomsvikings. Jomsborg's exact location, or its existence, has not yet been established, though it is often maintained that Jomsborg was somewhere on the islands of the Oder estuary. End of the Viking Age While the Vikings were active beyond their Scandinavian homelands, Scandinavia was itself experiencing new influences and undergoing a variety of cultural changes. Emergence of nation-states and monetary economies By the late 11th century, royal dynasties were legitimised by the Catholic Church (which had had little influence in Scandinavia 300 years earlier) which were asserting their power with increasing authority and ambition, with the three kingdoms of Denmark, Norway, and Sweden taking shape. Towns appeared that functioned as secular and ecclesiastical administrative centres and market sites, and monetary economies began to emerge based on English and German models. By this time the influx of Islamic silver from the East had been absent for more than a century, and the flow of English silver had come to an end in the mid-11th century. Assimilation into Christendom Christianity had taken root in Denmark and Norway with the establishment of dioceses