silver coins have been found in Sweden, particularly in Gotland. Variations in the size of the coin hoards show that there were phases of increased importation of coins and sometime decades during which very few coins were imported. The economic relationship between the Rus and the Islamic world developed quickly into a network of trading routes. Initially the Rus founded Staraya Ladoga as the first node from the Baltic to the Caspian Sea and Black Sea. By the end of the 9th century, Staraya Ladoga was replaced as the most important center by Novgorod. From these centers the Rus were able to send their goods as far as Baghdad. Baghdad was the political and cultural center of the Islamic world in the 9th and 10th centuries and the Rus merchants who went there to trade their goods for silver interacted with cultures and goods from the Islamic World, and also from China, India, and North Africa. The trade between the Rus and the lands south of the Black and Caspian seas made it possible for cultural interactions to take place between the Rus and the Islamic World. The account written by Ibn Fadlan about his 921–922 travels from Baghdad to the capital of the Bulghar kingdom gives details which can reveal the cultural interaction between the two groups. Ibn Fadlan gives a vivid description of the daily habits of the Rus, as well as the only known first-person account of the complicated ship-burning funeral ceremony. Certain details in his account, especially the dialogue of the ceremonies and his personal conversations with Rus individuals, show that the Rus and the Muslims were interested in and fairly knowledgeable about each other's cultures. The geography of the Volga region and the relative lack of physical wealth available for stealing (compared to targets of Viking raids in the west) made raiding a less important aspect of the Rus/Varangian activities in the East. Some raiding was necessary to gain initial control of the towns and regions that they developed into centers of economic activities. The first small-scale raids took place in the late 9th and early 10th centuries. The Rus' undertook the first large-scale expedition in 913; having arrived on 500 ships, they pillaged Gorgan, in the territory of present-day Iran, and the adjacent areas, taking slaves and goods. On their return, the northern raiders were attacked and defeated by Khazar Muslims in the Volga