One unusual aspect of warfare among opposing Viking groups was fighting in a so-called "hazelled field," described here by Ian Heath, an expert on medieval warfare:
The hazelled field [was] a specially chosen battlefield, fenced with hazel branches on all sides, where a battle was fought at a prearranged time and date by mutual agreement of the protagonists [opposing sides]. Once challenged to fight in a hazelled field, it was apparently a dishonor to refuse, or to ravage your opponent's territory until after the battle had been fought. . . . The latest reference to such a hazelled field that I am aware of dates to 978, when Earl Hakon Sigurdsson of Norway defeated King Ragnfrid (one of Erik Bloodaxe's sons) in a field marked out with hoslur [hazel branches].
Ian Heath, The Vikings. Oxford, Eng.: Osprey, 2001, pp. 32, 45.
With a certain amount of reverence," scholar Ian Heath points out,
Especially in the case of old swords that had been handed down from generation to generation or looted from burial mounds. A certain mystique clung to such weapons, which were usually given high-sounding names such as "Byrnie-biter," "Long-and-sharp," and "Golden-hilted." The very best swords were imported from the Frankish kingdoms, though Viking craftsmen usually fitted them with ornate hilts and grips of metal, bone, horn, and walrus ivory.33
These weapons were effective enough when used on an individual opponent in an informal, spontaneous military situation, such as a raid. But they were even more formidable in the more formal setting of a pitched battle. The number of fighters Viking leaders fielded for such battles was usually in the hundreds and only occasionally a few thousand.
Such a unit could do serious damage when it employed its most common offensive tactic—the shield-wall. This was a massive formation in which the soldiers stood in ranks (rows), one behind the other. Usually there were five or more ranks, with the better-armed men stationed in the front two ranks. These men raised their shields, which were touching, or even overlapping, and marched forward at the enemy. Only after they had made contact and sent their opponents reeling backward did they break ranks and fight individUally. The ninth-century Oseberg tapestry, excavated in southern Norway in 1904, shows part of such a shield-wall. And one is mentioned in King Harald's Saga—a part of Snorri Sturluson's Heim-skringla—in the section describing the battle of Stamford Bridge, against an English army: "Then King Harald arranged his army, and made the line of battle long, but not deep. He bent both wings of it back, so that they met together; and formed a wide ring equally thick all round, shield to shield, both in the front and rear ranks."34
Thus, the Vikings fought almost exclusively on foot. Unlike the Franks, who
The ranks of a medieval Viking shield wall are accurately reproduced by modern reeanctors. Such formations often had five or more ranks.
Were known for their cavalry units (horse-mounted fighters), the Norse rarely, if ever, trained horses for use in battle. Most often, Heath says, "they used horses simply as a means of increasing their mobility during their raiding expeditions. They either rounded up horses for this purpose in the vicinity of their encampment, or took those of a defeated enemy after a battle."35