The battles which the Vikings fought were fought on the sea more frequently than on the land.
Their warships were called long-ships and were half-decked. The rowers sat in the centre of the boat, which was low, so that their oars could reach the water. Sails were used, either red or painted in different stripes, red, blue, yellow, green. These square, brightly coloured sails gave the boats a gay appearance, which was increased by the round shields which were hung outside the gunwale and which were also painted red, black, or white. At the prow there was usually a beautifully carved and gorgeously painted figurehead. The stem and stern of the ships were high. In the stern there was an upper deck, but in the forepart of the vessel there was nothing but loose planks on which the sailors could step. When a storm was raging or a battle was being fought, the loose planks did not, as you may imagine, offer a very firm foothold.
The boats were usually built long and pointed for the sake of speed, and had seats for thirty rowers. Besides the rowers, the long-boats could hold from sixty to one hundred and fifty sailors.
Merchant ships carried cargoes of meal and timber. They were built much as were the long-ships, but as they had no shields hung around the gunwale, it was easy to see whether a vessel were a warship or a merchantman.
On land or on sea the weapons which the Vikings used were the same—swords, spears, battle-axes, clubs, bows and arrows. When Viking fleets met an enemy, they would blow a ringing blast on their horns, hoist their standards, and then, tying the stems of their ships firmly together, they were ready to fall upon their prey.
As the ships drew closer together the Vikings would throw out grappling-hooks and drag the enemy's ships alongside their own. No sooner was this done than some of the bravest of the Viking crew, led by their chiefs, would leap on board the enemy's ships. Then using sword and spear, battle-axe and club unsparingly, they would rid themselves of their foes. The decks would soon be cleared, and the ship and its treasures become the prey of the victorious Northmen.
If a great battle were before them, the Viking chiefs picked their crew with the utmost care. No one younger than twenty or older than sixty years of age was chosen, and these were all noted for their valour and their strength.
The struggle was usually fiercest near the prow and the stern of the ship. Here the king and the chiefs would take their stand, while around them pressed their most valiant followers. Near them stood the standard-bearer waving on high his banner.
Sometimes the Vikings would stretch chains or cables across the entrance to a harbour, and these endangered the vessels of those who might seek to enter and attack them unawares.
Indeed, once a jarl named Hakon rowed his long-ship into the Sound between two vessels which he thought were merchantmen.
Perhaps it was not by any mistake that the war-shields had not been hung over the gunwale; perhaps the Vikings were hoping to catch Hakon jarl in a trap. Be that as it may, the ships which Hakon thought were harmless merchantmen were in reality Viking long-ships.
As the keel of Hakon's vessel was passing over the cable which had been stretched across the opening into the Sound, the Vikings began to haul it in with a windlass. Soon the cable touched the bottom of the vessel, and the stern began to rise while the prow was plunged forward so that the water rushed into the ship. Before Hakon and his men could do anything to save themselves the ship was filled and upset. Hakon jarl had indeed been caught in a trap.
If you ever go to Christiania you will see the ruins of one of these old long-ships in the museum there, for the Gökstad vessel of which I have told you was built very much as any other warship of the Viking age.