Extremely Effective Tactical Formations Of Military History


The formation of a unit could be decisive in a battle. In a case where all things were otherwise equal, the commander who knew how to organize and deploy his forces effectively had the decisive advantage. Throughout history, there have been several formations that worked very well, and some have had multiple variants that remained popular with commanders through the centuries.

Flying Wedge

The wedge formation is a very old and very effective formation when employed correctly. Historically used with cavalry, the formation involves a mass of troops in a triangular wedge with the tip charging at the enemy. The ensuing charge would penetrate into the ranks of the enemy, usually infantry, and scatter the opposing force. When charging thinner lines, the wedge could completely separate a line into two groups, dividing a force and making them easier to defeat.

In antiquity it was often used by heavy infantry to break static shield walls, forcing the defenders to fight individually. The heaviest Cataphract cavalry could be very successful with wedge formations, their sheer momentum being able to drive deep into enemy formations. Some Germanic armies and Vikings used a modified wedge formation to house skirmishers in the center and deployed spearmen on the flanks at the base of the wedge. It was intended to quickly break an enemy, but if it didn’t, it could become surrounded and then easy to combat.

Alexander the Great personally led his cavalry in a flying wedge to great effect in many battles, most notably his resounding victory at Gaugamela. The wedge could also be applied to multiple unit formations. An army in a hollow wedge with a reinforced center could overwhelm the enemy center, while withholding and protecting vulnerable flanks, potentially winning the battle after engaging less than half of their forces.

The Flying Wedge was also used to great effect during the era of the Napoleonic wars. Cavalry armed with guns could maximize their fire and then utilize lances or sabers to punch through the thin firing lines.

From left to right: standard single unit wedge as a cavalry charge might use, army organized into massive wedge, and soldiers patrolling in a wedge formation.
From left to right: standard single unit wedge as a cavalry charge might use heavily armored soldiers or officers on the tips, the army organized into a massive blunted wedge, and soldiers patrolling in a wedge formation.

The wedge is used today in various roles though its function is slightly different. Armored vehicle wedge formations as well as light infantry wedges allow for visibility and supporting fire by each unit while affording the opportunity to get maximum firepower in a fight. Riot police will often employ a wedge to divide small groups or to separate thin lines in two manageable groups.

Macedonian phalanx

Phalanx/Firing Line

Though lumping together the Macedonian sarissa pike phalanx with early firearm firing lines might seem strange at first, they actually operated on the same principal. The Greek Hoplite phalanx emphasized teamwork, but also required great individual talent. While the Macedonian phalanx still required excellent discipline, it focused on the collective devastation of a barrage of spear points.

The 13-20 ft long sarissa spears were terribly unwieldy for one-on-one combat, but when the average soldier charged at a Macedonian phalanx they had to fight through 5-10 thrusting spears before even reaching the front lines. By organizing a dense line, the soldiers needed only to thrust their spears forward, and the line formation did the rest.

The line pike formation saw use periodically through antiquity and the middle ages as a tactic against  cavalry formations, but became very popular again with the adoption of handguns. Early firearms were quite inaccurate due to lack of rifling and aerodynamically shaped bullets and many other variables such as the type of powder and loading techniques.

A line of infantry preparing to attack.
A line of Prussian infantry preparing to attack.

A musket man would have to hope for a lot of luck to hit a single charging cavalryman. Considering that firearms were inaccurate but incredibly lethal, commanders began massing their men close together and firing volleys in the general direction of the enemy. Some shots were guaranteed to land and all in unison. The sudden impact of a volley, or a quick succession of volleys by kneeling the first line and firing with the second line, greatly affected enemy morale. It may seem strange seeing how firing lines worked, especially when watching movies on the Revolutionary, Civil, or Napoleonic wars, but it was really the most effective way to fight.


Hollow Square

The hollow square formation had its heyday during the firearm line formation period described above, but it originated in ancient times. It was used with great success by the 10,000 Greek mercenaries during their lengthy retreat from central Persia. under heavy attack and constant missile fire the Greeks formed a massive moving hollow square to protect their noncombatants and baggage. The heavy infantry repelled charges and allowed their long range skirmishers to fight back from the safety of the square.

The Roman commander Crassus would also employ the square at the battle of Carrhae, but it failed in this instance as the enemy Parthians had an ample stockpile of arrows to wear down the legionaries from afar. The square seems to have been occasionally utilized by Asian armies as well, often to repel cavalry charges.

In the age of the Napoleonic wars the hollow square developed into a highly flexible formation. Soldiers formed an infantry square almost always in response to cavalry charges. Cavalry during the Napoleonic wars could be especially deadly, being armed with handguns, but also with lances and sabres and had the speed to close on a formation quickly.

Cavalry couldn't hope to do much of anything against a well-formed infantry square.
Cavalry couldn’t hope to do much of anything against a well-formed infantry square.

Infantry squares were organized in groups of 500 to 1,000, sometimes more, with sides being at least two men deep. Corners were reinforced and occasionally stuck out to provide enfilading fire, though this was not common.  The square sometimes held supplies or provided reinforcements, but the internal space was vital as the lines had to be able to flex to absorb cavalry charges.

Battlefields could feature multiple hollow squares supporting each other and armies with skilled officers could actually make these squares mobile and use them offensively, making them static only to hold up against charges when needed. At the battle of Waterloo, some hollow squares were able to stand up to almost a dozen separate cavalry charges. The only downside was that a broken square was often a disaster, leaving the infantry vulnerable from all sides and likely to lower the morale of nearby squares. It was very rare for a square to reform after one or more sides collapsed.

After the Napoleonic wars the square was still used occasionally, but more in the way the ancients utilized it, for overall protection. Large, often rectangular formations were used during colonial wars against warriors armed with less advanced weapons. The square allowed a unit to be almost completely enveloped by an enemy, but still able to keep composure and use its firepower to the maximum.

A battalion of the U.S. Army Coast Artillery Corps demonstrating the hollow square formation used in the event of a street riot, 1918. - NARA / Public Domain
A battalion of the U.S. Army Coast Artillery Corps demonstrating the hollow square formation used in the event of a street riot, 1918.

The hollow square  became redundant with the adoption of more rapid firing weapons. One of its last successful uses was by a small U.S. cavalry detachment of 87 men, who were ambushed by 400 Cheyanne cavalry. After forming a hollow infantry square and placing their horses in the center, the men marched on a fighting retreat for eight miles until the Cheyenne gave up and withdrew. Hollow squares can still be used in certain situations, such as the protection of the wounded during riots or in the case of ambushed units.

It seems likely that the three tactics and formations discussed above will remain part of warfare in the future.

By William McLaughlin for War History Online