Two areas of the Carolingian empire came under attack are Frisia, and Aquitaine. In Frisia the Vikings' principal targets were trading centres, particularly the prosperous market of Dorestad, which was first sacked in 834. The Anglo-Saxon Chronicle provides nearly all the information about the Viking raids. From 876 to 911, the Scandinavians capitalised on the position of strength to colonise areas of England and Francia. In 876 the Anglo-Saxon Chronicle contained the significant report: 'In this year Halfdan shared out the lands of the Northumbrians, and they proceeded to plough and to support themselves'. Scandinavian chiefs ruled large tracts of Frisia for long periods without any apparent attempt by their followers to colonise the region, and until the mid-870s the armies which occupied Frankish or Anglo-Saxon territory over many years likewise gave no indication of wishing to take political control. The raids were motivated by militant paganism, there is equally little support for this in contemporary sources.