The image of the societies of Scandinavia in the late Iron Age has been based predominantly on their economic character, involving aspects such as agriculture and settlement, economy and society, trade and urbanisation. What are known as the Middle Ages in Scandinavia begin around the year 1000, half a millennium later than for the rest of western and central Europe. Only from this date onwards did Scandinavia consist of unified kingdoms and was Christianity established as a serious force in pagan Scandinavia. Much of what was written about Scandinavian history actually comes from Iceland. In Europe, the roman script was adopted at an early date, and only in Scandinavia did the runic script develop further during the Viking period. The settlement structure in late Iron Age Scandinavia clearly developed hierarchically with respect to size and function. Myths played a vital role in the creation of a political mentality amongst the new Germanic warlords and kings in Europe.