The Svinfylking, Old Norse for "swine array" or "boar snout",^[1] was a formation used in battle. Related to the wedge formation, it was used in Iron Age Scandinavia and later by the Vikings.^[2] It was also used by Germanic peoples during the Germanic Iron Age and was known as the "Schweinskopf" or "Swine's Head".^[3] Its invention was attributed to the god Odin.^[3][4]

The apex was composed of a single file. The number of warriors then increases by a constant in each rank back to its base. Families and tribesmen were ranked side by side, which added morale cohesion.^[5][3] The tactic was admirable for an advance against a line or even a column, but it was poor in the event of a retreat.^[3]

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, which caused complete chaos for the horses. The Svinfylking could also be used as a wedge to break through enemy lines. Several Svinfylking formations could be grouped side by side and appear something like a zig-zag to press or break the opposition's ranks. Its weakness was its it inability to handle flanking. The Svinfylking was based on a monumental shock, and unless it broke the enemy lines immediately, its warriors would not hold long.^{[6][unreliable source?][citation needed]}