The first men to appear in what is now Norway emerged from dim pre-history when the great inland ice sheets were retreating over Scandinavia. Ten thousand years ago the forefathers of today's Norwegians hunted reindeer and other prey on their long trek north. The land they came to had for centuries borne the weight of the icecap, so the ocean met the shore 200 metres higher up than is the case today. The oldest proof of human activity was discovered on a hill in the southeast region of Østfold County, not far from the southern frontier with Sweden. At that time the hill was probably an offshore island, just south of the glacier tip.
Although there is no general agreement on where the ancestors of today's Norwegians came from, or by which routes they journeyed to the north, it is almost certain that one of these routes passed through Østfold. Artefacts found at settlements there are of the same type as those discovered in southern Sweden and in Denmark. Another possible route may have led from what is know today as the North Sea continent to southwest Norway.
These first Norwegians were hunters who settled in small groups. Their existence is revealed in the flint tools, clay vessels, and perhaps most spectacularly, the rock carvings they left behind. Examples of their art remain in virtually every part of Norway, hewn or ground into the rock. The carvings tend to depict their prey: reindeer, moose, deer, bears and fish. More seldom, but no less impressive, are their depictions of people or boats.
The transition to agriculture started in Norway approximately 5,000 to 6,000 years ago, initially in the area around the Oslo Fjord., Archaeological finds from the Bronze Age (1500 - 500 B.C.) are dominated by the cultural relics of farmers, particularly in southern Norway. Finds from this same period in northern Norway show that the people there were hunters. The remains of sizeable settlements of hunters found at many locations in Finnmark, far to the north, offer clear proof of seasonable cooperation between many individuals.
Grave finds from the Roman Age (0 - 400 A.D.) show that there were links with civilizations to the south. Discoveries include utensils of bronze and glass as well as weapons. The art of writing, in the form of runic letters, also became known in the Nordic lands at this time.
The migrations of 400 to 550 A.D. were a restless period of continental Europe's history, and artefacts found in Norway indicate that the same conditions prevailed there too. The existence of farms in marginal areas indicates that settlement had reached a saturation point. Pollen analyses reveal that the coastal areas to the west at this time were deforested. The troubled times led tribes to establish defence systems such as fortresses, the remains of which are evident over a stretch of 50 km along the eastern banks of Norway's largest lake, Lake Mjøsa.