Svinfylking
The Svinfylking, or the 'Swine Array,' or Boar Snout, was a version of wedge formation used by the Vikings and earlier Germanic peoples. The formation consisted of heavily armed, presumably hand-to-hand warriors and less-armored archers grouped in a triangle formation with the warriors in the front lines protecting the archers in center or rear. Cavalry charging a group in Svinfylking formation were frequently attacked by the outer warriors with spears causing complete chaos among the horses. The Swine Array could also be used as a wedge to break through enemy lines. Several Svinfylking formations can be grouped in a side by side appearing something like a zig-zag to press or break the opposition's ranks.
The weakness of the swine array was that it could not handle flanking. Swine array was based on a monumental shock. If the swine array did not break the enemy lines immediately then the men in the swine array would not hold long.