Large finds of finished ornaments and weapons show a comparatively rich culture. This was emphasised by elaborate burial rites, the dead laid in single graves under mounds of earth and stone. The deterioration of the Scandinavian climate in the last millennium before Christ coincided with the advance across Europe of the Celts, which halted the flourishing trade of the Swedish settlers. With the new millennium, Sweden made its first mark upon the Classical world. Pliny the Elder (2379 AD) in the Historia Naturalis mentioned the "island of Scatinavia" far to the north. Tacitus was more specific: in 98 AD he referred to a powerful people, the Suinoes, who were strong in men, weapons and ships: a reference to the Svear, who were to form the nucleus of an emergent Swedish kingdom by the sixth century. The Svear settled in the rich land around Lake Malaren, rulers of the whole country except the south. They gave Sweden its modern name: Sverige in Swedish or Svear rike, the kingdom of the Svear. More importantly, they gave their firs; dynastic leaders a taste for expansion, trading with Gotland and holding suzerainty over the Aland islands. The Viking period The Vikings raiders and warriors who dominated the political and economic life of Europe and beyond from the ninth to the eleventh centuries came from all parts of southern Scandinavia. But there is evidence that the Swedish Vikings were among the first to leave home, the impetus being a rapid population growth, domestic unrest and a desire for new lands. The raiders turned their attention largely eastwards, in line with Sweden's geographical position and knowing that the Svear had already reached the Baltic. By the ninth century the trade routes were well established, Swedes reaching the Black and Caspian seas and making valuable trading contact with the Byzantine Empire. Although more commercially inclined than their Danish and (Norwegian counterparts, Swedish Vikings were quick to use force if profits were slow to materialise. From 860 onwards Greek and Muslim records relate a series of raids across the Black Sea against Byzantium, and across the Caspian into northeast Iran. But the Vikings were settlers as well as traders and exploiters, and their longterm influence was marked. Embattled Slavs to the east gave them the name Rus, and their creeping colonisation gave the area in which the Vikings settled its modern name, Russia. Russian names today Oleg, Igor, Vladimir can be derived from the Swedish Helgi, Ingvar, Valdemar. Domestically, paganism was at its height. Freyr was "God of the World", a physically potent God of Fertility through whom dynastic leaders would trace their descent. It was a bloody time. Nine human sacrifices were offered at the celebrations held every nine years at Uppsala. Adam of Bremen recorded that the great shrine there was adjoined by a sacred grove where "every tree is believed divine because of the death and putrefaction of the victims hanging there".