Flying wedge

A flying wedge (flying V or wedge also boar's snout or svinfylking ) is a configuration created from a body moving forward in a triangular formation. This V-shaped arrangement began as a successful military strategy in ancient times when infantry units would move forward in wedge formations to smash through an enemy's lines. This principle was later used by Medieval European armies, as well as modern armed forces, which have adapted the V-shaped wedge for armored assault.

In modern times the effectiveness of flying wedge means it is still employed by civilian police services for riot control. It has also been used in some sports, although the use of wedges is banned due to the danger it poses to defenders.

Greeks and Romans
The wedge (έμβολον, embolon in Greek; cuneus in Latin, colloquially also caput porcinum, "boar's head"), was used by both infantry and cavalry. The men deployed in a triangular or trapezoid formation with the tip leading the way. According to Arrian and Asclepiodotus, the wedge was first used by the Scythians, and then the Thracians. Philip II of Macedon adopted it from them as the main formation of his Companion cavalry and Alexander the Great faced Persian cavalry arrayed thus, as Arrian attests. The use of this formation enabled the concentration of missiles against a limited front and thus was used not only to smash into the enemy line, but to also add to the effectiveness of long range, usually hurled weapons like javelins and hand axes. As an infantry formation it is attested by Frontinus to have been used by the Romans in Pydna against the Macedonian line of Perseus. It was also used to great effect by the Roman legions, with the wedge proving effective in campaigns in Britain, such as during Boudicca's Revolt, where a greatly outnumbered Roman army used it to defeat the Iceni. In the Late Roman army, several cavalry units were designated as cuneus [equitum].

Germanic wedge formations
Keilerkopf or Keil (wild boar's head, wedge, Latin: cuneus, meaning throng ) is a German phrase to describe the attack formation ("Tactical body") of the prehistoric infantry of the Celts and Germanic tribes. It is generally believed that the Germanic tribes were more successful with this tactic than the Celts. It was used to force the Roman forces to split and was later applied specifically to the weakest units.

Due to the high difficulty of this formation and the relatively high probability to fail it is assumed that the front lines were filled with the best warriors of the Germanic sibbs who had to break the Roman front line.

Here the individual warrior tried to gain fame and glory in the battle. The most distinguished princes and their acolytes stood at the head of the Keil. However, this was also the greatest mortal threat. But an army leader who survived a lost battle had forfeited his life (usually suicide). Warriors who had fled were hanged or slain.

According to the Roman historian Tacitus, the Keil was a tightly packed crowd, strong on all sides, not only in front and back, but also on the flanks. The formation was not like a wedge but more like a rectangle with forty warriors in the first line and 1,600 men strong. In this formation, the wingmen are at most risk. It was therefore well possible that the wing marched with some caution and held back a bit, so that the center stormed further and looked like a wedge. The outer ranks of the rear on the other hand swelled slightly. The goal was to hit hard at the same time and to drive a 40 yard wide hole into the enemy line, according to the German historian Hans Delbrück.

When the Germanic Keil was advancing against the enemy, they sang the baritus or barditus, the battle song (battle cry); it begins with a muffled grumbling and swells with the heat of the battle up to the roar of the waves beating against the rocks. According to Germanic legend and Tacitus, Hercules once visited German soil and they sang of him first of all heroes.

The Middle Ages
In the Middle Ages, the tactic was especially effective against defensive shield wall formations when defenders would link their shields together to form an all-but impenetrable barrier. Armored, heavily-armed infantry could use their momentum in wedge formation to drive open small sections in the shield wall. This would break up the shield wall exposing the defenders to flank attacks.

Western Europe
Two complete descriptions of an infantry wedge are given by Saxo Grammaticus in his Gesta Danorum. In Book I, he describes a shallow wedge, with the front rank of two men then each thereafter doubled. In Book VII, he depicts a sharper pointed formation 10 men deep with the first rank being composed of 2 men, each rank composed of 2 more. Thus, each wedge was composed of 110 men, 10 deep, 2 men on its tip, and 20 on its base. According to the Vikings, the wedge formation, called by them svinfylking, cf. the Latin caput porcinum, was invented by Odin himself.

A triangular or wedge formation was also used in the medieval period by the Flemish and Swiss infantry

Deep wedges of cavalry were used by German armies in the later Middle Ages. At the Battle of Pillenreuth in 1450, both the armies of Albrecht Achilles and Nuremberg fought in wedge formation. The Nuremberg cavalry was drawn up in a wedge led by 5 picked knights, then seven, then nine, then 11. The following twenty ranks held 250 ordinary men-at-arms, then a final rank of 14 picked men to hold the formation together. Sir Charles Oman refers to an unpublished manual of 1480 by Philip of Seldeneck which describes the formation, calling it the Spitz. He gives examples of various formations varying from 200 men to 1000. The formation of 1000 men places seven men in the first rank, with each rank increasing by two men back to the eighth rank with 21. The remaining men are in a column 20 men wide behind the point. The banner would be carried in the seventh rank.

Byzantium
Byzantine Emperor Nikephoros Phocas analyzes the wedge formation of the Byzantine Cataphracts in the third chapter of his Praecepta Militaria. There, he relates that the wedge must be formed by 354 cataphracts and 150 horse archers to a total number of 504 men. The row of the first line comprised 20 horsemen, the second 24, the third 28, down to the 12th line, which consisted of 64 men. If such a number of men is not available, he proposes that the wedge be formed by 304 cataphracts and 80 horse archers, or a total of 384 men, the first line comprising 10 men. In his next chapter (Ordinance on Cavalry Deployment), he ordains that the wedge must be accompanied by two cavalry units, which will guard its flanks. A wedge whose ranks are not complete in the middle is shaped as an Λ instead of a Δ and is called a hollow wedge, or in Greek κοιλέμβολον, koilembolon.

Modern warfare
The wedge is still used in modern armies, especially by tanks and other armored units. An example of this is the Panzerkeil or "armored wedge" used by the Germans in World War II.

Drill formation
The wedge formation is used ceremonially by cadets at the United States Air Force Academy during the annual graduation parade, when the soon-to-be commissioned first-class cadets (seniors) leave the Cadet Wing. This is the reverse of the acceptance parade, held each fall, when the new fourth-class cadets (freshmen) join the Cadet Wing in the inverted wedge formation.

Policing
Police riot squads sometimes charge in flying wedge formations, to break into a dense crowd as a snatch squad to arrest a leader or speaker, or to chop a long demonstration march into segments. It can also be used to escort VIP's through hostile crowds.

Sports
Although originally permitted in most full contact team sports, the use of the flying wedge is now banned for safety reasons in Rugby union, Rugby league and American football. The principle is similar to the military application, the ball carrier starts an attack and is joined on both sides by team mates who drive them forward towards the goal line. However due to the number of serious injuries related to the flying wedge, any attempt at this formation is now punished by in-game penalties.

In American football, the formation was first introduced by Harvard in an collegiate game against Yale in 1892. But despite its practicality, it was outlawed two seasons later in 1894 because of its contribution to serious injury. Nevertheless its concept continued to influence several football plays in the modern game, until 2009 when NFL league owners agreed to strengthen its ban to completely disallow any type of blocking wedge formation.