The military history of Finland consists of hundreds of years of armed actions in the territory encompassing modern Finland. Prehistory Finland was first settled around 8300 BC, immediately after the last ice age. Archaeological evidence of prehistoric warfare is largely incomplete, primarily because prehistoric skeletons, which might bear traces of violent traumas, rarely survive in the Finnish soil. From the Bronze Age (1500–500 BC) onwards, improved weapons, such as battle-axes and swords, are included in the archaeological record. There is also evidence of hill-forts from the same time period. Weapons are common finds from the Roman Iron Age (1 A.D. – 400 A.D.) onwards. Middle Ages Viking attacks on Finland are indicated only by a couple of runic inscriptions in Sweden, as well as some uncertain saga sources. According to one saga, Olaf the Holy, later a King of Norway, made an attack on a country that has often been interpreted as south-western Finland; he was defeated. Before the 14th century Finnish history is very poorly documented. However, archaeological evidence, for example hill-forts, suggests that the 12th and 13th centuries were relatively restless, as Sweden and the Russian state of Novgorod were slowly spreading their dominance in Northeastern Europe. The Swedish kingdom championed Roman Catholic Christianity, whereas Novgorod was an Eastern Orthodox state. Several raids and attacks against the Finns are mentioned in Russian chronicles during the 12th and 13th centuries. Both Swedes and Danes made offensives against the Finns. These operations were dubbed as "Crusades" in later historiography. According to the Icelandic Egil's Saga, the Norse and the (Northern) Fennic people united their forces, apparently during the 12th century, against attacks by the Karelians who—with the assistance of Novgorod (part of today's Russia)—made advances towards Northern Finland and Norway. According to some sources, the Karelians destroyed the Swedish town of Sigtuna in 1187. In 1251 the Finnish Karelians again fought against the Norwegians, and in 1271 the two Finnish peoples, the Kvens and the Karelians, cooperated in wars and battles against the Norwegians in Hålogaland (Haalogaland). Finland as a part of Sweden During the several following centuries, a gradual and slow process of Swedish expansion in today's Finland and the consolidation of Sweden took place, not through wars fought between the Finns and the Swedes, but rather by various levels of wars and skirmishes between the Finns themselves, others—in the west, such as the people of Häme—sympathising with the