'Faster' Harald ordered his army.
He is anxious and worried sick. He is hastening his march all the more because he had heard that the lands near the Dragon camp were being laid to waste.
Dantes is said to suffer the most with almost all the villagers exterminated, corpse littered the Old Empire road, and river of blood has been shed around that area.
And Harald is also worried about his newborn son, Herod Alan and his wife Emilia safety. However, that is not all that make Harald to march faster to Arleans.
Although the devastation of many of his territory may have played a part in his decision, he has a tactical reason, too, to advance swiftly and pin Arial before he reached Arleans, where the isolated invaders would eventually run out of supplies.
And Harald knows that such an army that Arial had brought will be met by resistance by those armies he left in the area near Borveaux.