After Ivar had landed his forces and sent men on horseback to reconnoitre, Decius and Curtius, the centurions who commanded the stronghold at Bononia (the modern Boulogne), seeing that the Viking force was much smaller than their own, resolved to attack them, and an overpowering Roman force left their stronghold with the hope of annihilating the Norsemen who had dared to land before their eyes.

When Ivar saw this, he said to his men, “Often the more numerous host does not gain the victory if there are fearless men against it. Many a blunt sword has won the victory in battle. As we are the weakest in number, let us arrange our host in the wedge shape that was taught to our forefathers by Odin himself; and we will have, besides, another body of men to attack the Romans or protect us, as may be necessary.”

When Decius saw this strategy carried out, he marvelled greatly; for the Romans thought this peculiar war formation, which they called cuneus, was only known to them. He had heard from different Roman commanders that the Vikings had this knowledge, but he had not believed them; and though a moment before, he had boastingly told his soldiers that Rome would soon hear of their victory, he became uneasy as he saw the glittering shields and helmets of the Vikings in their battle array, and the body of archers and horsemen with shining swords, who were ready to go wherever sent.

He then ordered his men to be placed in wedge-shaped formation. When Ivar and his men saw this, they in their turn wondered how it was that the Romans knew this formation, and Hjalmar exclaimed: “They must have learned this from our people; how could it be otherwise?”

Before the battle, Ivar issued his orders, saying, “Our horsemen will remain on the lookout, and be ready to support us or to attack the enemy; our archers will pour a continuous hail of arrows upon the Romans, and our slingmen will do likewise with stones. The shield-burg should be at the apex of the triangle, and must be guarded by the most skilful warriors; for if it is broken or opened, especially in the beginning of the battle, it will be most fatal to victory. The two other points of the triangle must also be very strongly guarded. It is imperative that great care be taken that our locked formation be not broken or even opened; for disorder in our midst would follow, and might lead to great disaster.”

The foster-brothers agreed that as Ivar was the foremost champion among them, he should be at the apex of the triangle with their most valiant men, for this part of the triangle was always the weakest spot of the formation.

Then Ivar said: “Let my standard ‘Victory’ be moved forward, and let Alrek, my standard-bearer, be surrounded by berserks. My scalds must stand in the midst of the shield-burg, and so placed as to be able to see the conflict, and praise the deed of the combatants, or of those who fall in the battle.”

When Alrek heard this he said: “I have feared for some time past, during the years that this long peace has lasted, that I should die of old age on my bench, and I wished rather to fall in battle, if it had thus been fated me by the Nornir.”

Sigmund and Sigurd, with their two standards and their valiant men, were at the two other points of the array. Hjalmar and a large body of men were in front of the standards of Ivar to protect the apex of the triangle, or to attack the Roman host if need be, if these did not come forward.

The war-horns were sounded on the Norsemen’s side, and the archers and slingmen advanced towards the Romans, and poured a storm of missiles into them which made many of their host bite the dust; then a general attack took place, and after a fierce conflict of spears and swords, and desperate efforts of the Romans to protect themselves with their shields, their formation was broken after much slaughter, and they fled in every direction before the victors. Curtius, one of the centurions, was killed; but Decius and a number of his men escaped under the cover of their fortifications. From their walls the Roman centurion looked upon his fallen soldiers and the victorious Norsemen, and exclaimed in a voice full of despair: “Rome, what has become of thy might, that thou canst not conquer those men of the sea? They defy thy power, and laugh at thy legions sent against them! To-day they are here, to-morrow elsewhere. No province is free from their attacks. Even if a country is powerful with its legions on land, it cannot hold sway over the world unless mighty at sea also.”