An 863 entry of the Annales Bertiniani reports "In January Danes sailed up the Rhine towards Cologne, after sacking the emporium called Dorestad and also a fairly large villa at which the Frisians had taken refuge, and after slaying many Frisian traders and taking captive large numbers of people. Then they reached a certain island near the fort of Neuss. Lothar came up and attacked them with his men along one bank of the Rhine and the Saxons along the other and they encamped there until about the beginning of April. The Danes therefore followed the advice of Hrørek and withdrew by the same way they had come." The entry makes clear that another group of Danish raiders had attacked Dorestad before traveling upstream to Xanten. However a rumour soon circulated that Rorik had encouraged the raiders on their expedition. Coupland dismisses the idea that Rorik could have invited a raid on his own area. He suggests the rumour was based on his method of getting rid of the invaders. Rorik could have protected his own territory by convincing the Danes to travel further up the river, effectively letting them become other rulers' problems. Coupland notes it would not be a unique case in the 9th century. The Siege of Paris from 885 to 886 under Sigfred and Rollo had not ended with mutual annihilation. Charles the Fat had simply allowed Rollo to go and plunder Burgundy.