In about 300 AD, a Germanic settlement was the first permanent town on a complex of low river dunes. Whereas many such settlements were abandoned in the early Middle Ages, Zutphen on its strategic confluence of IJssel and Berkel stayed. After the incorporation of the IJssel lands in Charlemagne's Francia, Zutphen became a local centre of governance under a count. The Normans raided and ravaged it in 882. Afterwards a circular fortress was built to protect the budding town against Viking attacks.