Iceland was settled by Nordic and Irish peoples around the peak of the viking period, around the year 900, at a time of great upheaval in northern Europe. An organised state was established where there was no monarchy, but where the heads of major families ruled according to a well developed legal system. This sytem of government existed until 1262 when Icelanders came under Norwegian rule. They adopted Christianity in the year 1000 and soon afterwards the literature of Christian cultures reached Iceland. Icelanders began writing in their own language around 1100 and over the next few centuries produced both remarkable documentary and fictional works, including the Sagas and the Eddakvæði.
From early on the forces of nature have affected the Icelanders´ life and survival. Up until the beginning of the century the country was a primitive community of farmers and fishermen. The industrial revolution in Iceland was mainly apparent through the mechanisation of the fishing industry and over the past century this has led to the development of a modern technical and social sytem.
On the average, there are volcanic eruptions every five years in Iceland. As the geology map shows, most activity occurs quite far from the more densely populated areas which are mainly along the coast. As a result volcanic eruptions have caused less damage than might be expected at first sight. Nevertheless, considerable reduction of livestock has often followed eruptions, especially near to volcanoes. Settlements and fields have been consumed by lava, while ash or tephra fall has destroyed grazing land and poisonous gases have led to pollution and vegetation damage. Ash fall also plays a part in one of Iceland´s major problems, the loss of valuable farm land by wind erosion.
The greatest threat, however, comes from catastrophic floods (jökulhlaup), the result of subglacial eruptions. They stop at nothing which may be in their path and have often caused great destruction and even wiped out entire settlements. Such was the case in 1362 when an eruption of Öræfajökull led to the depopulation of an entire county. The power and amount of sediment in such floods can push the coast outwards by several kilometres as happened following the eruption of Katla in 1918.
Earthquakes are also frequent in Iceland and have often caused great damage.