Every aspect of life in Sparta was geared toward the benefit of its military, which in its own time was widely considered the most effective infantry force in the Greek world. The military itself was a part of the life of Sparta, and vice versa. Indeed, few other cultures in the history of the world have ever geared themselves so totally to the arts of war as did Sparta at the height of its power.
As has been mentioned several times in the preceding history of Sparta, the basic formation of the Spartan military was the phalanx, a tight formation of heavily armed and armored hoplite infantrymen. At the front rank of the formation, the bronze-covered wooden shields of the hoplites would be overlapped in order to form a type of mobile protective wall. Long spears would then be used by the front ranks to strike out at the enemy as the phalanx advanced or as the enemy moved on the phalanx. In the case of a moving phalanx, enemies could end up crushed under the feet of the advancing infantrymen or killed by the second rank of soldiers. In the case of a static formation, as at Thermopylae, a tight phalanx could stand up to the assault of an enemy force many times larger, provided that the flanks of the phalanx were secured and that a flanking maneuver could not be executed.
Though the spear was the primary weapon used in conjunction with the phalanx formation, it was susceptible to being broken. In this instance, the Spartan hoplite could switch to a sword or to using the spike that was traditionally placed at the rear end of a spear as an offensive weapon. The shield would be held in the left hand, while the right was used to wield the spear or sword that the hoplite was using at the time.
When arranged for battle, the elite elements of the Spartan army would find themselves clustered on the right flank (as at Leuctra) to prevent a flanking maneuver from being executed by an enemy. This would generally include the hippeis, if a Spartan king was deployed into the field. Before the beginning of a battle, as is common in many global military traditions, the Spartans would chant a type of battle hymn known as a paian, probably accompanied by a type of flute music. This music would help to focus the minds of the warriors for battle and to remind them of the duty that they owed to Sparta as soldiers. This, combined with years of intensive training, would ensure that every man in the phalanx line would hold his position. Social pressure, too, would have played a role, as there were few things less tolerated in the Spartan society than cowardice in battle.
However, it should be noted that the Spartan army rarely fought alone. To begin with, Spartiates were generally accompanied by many Helots who were bound to serve them in battle (sometimes with ratios as high as seven Helots to each Spartiate). Perioeci, too, were frequently involved in the military conflicts of Sparta. In addition, Sparta would frequently field armies led by Spartans but consisting of soldiers from the many city-states of the Peloponnesian League and other allies. By this method, the comparatively small but disproportionately powerful Spartan army could fight effectively against much larger forces. This type of alliance army was common for the city-states of Greece in war, as few of them could field a large army on their own.
At sea, the Spartans were, for most of their history, a much weaker power than their Athenian neighbors to the north. This briefly changed under Lysander's naval command, but the fleet of Sparta was not as important to it as its land forces. For this reason, it was common practice for it to engage the fleets of its allies in war, particularly Corinth. At any one time, the Spartan fleet was commanded by a single general, known as the navarch. The navarch of the Spartan fleet could only serve for one year and could not hold the post twice.
Underlying both the actions of the Spartan military and the many elements of Spartan life that were geared toward facilitating those actions was a code of honor that governed the behavior of the Spartan solider both on and off of the battlefield. Spartan soldiers, though expected to be heroic and, indeed, to die for Sparta if the circumstances made such a sacrifice inevitable, were taught that they should fight with the desire to live and fight again, rather than entering the battle without a care for their own lives. Stoic calmness, rather than blind rage, was the norm expected of the Spartan hoplite, even in the thick of a battle. True to the long-standing use of the phalanx formation, this code specifically forbade hoplites from dropping their shields, thus creating an opening in the otherwise impenetrable wall of shields at the front of the formation. This same code of honor applied, if in a different manner, in the daily life of the Spartan soldier. A Spartan was to remain stoic and cool-headed at all times, rather than giving into rage or fits of emotion. In this sense, this code of conduct may be seen as an analog to the medieval code of chivalry, although the core values of the two cultures expressed through these codes are, of course, different in many ways.