The Spanish tercio is a large infantry regiment, consisting of three thousand pikemen, musketeers, and arquebusiers in a mutually supportive formation. Also known as the Spanish Square, it is similar to the Swiss square. It was widely adopted across Europe, particularly in the Holy Roman Empire, and has only recently begun to be challenged successfully, most notably by the tactics of Maurice of Nassau at the Battle of Nieuwpoort in 1600.

The Spanish tercio forms the backbone of the most successful army in the world. It containes pikes, some sword-and-buckler men, and light firearms organized under captains and colonels. Spain has an efficient organization for recruiting from its own provinces and keeping these units “topped up.” The endless campaigns in Italy and the Low Countries make them formidable troops, with high confidence and esprit de corps.

The tercio is composed largely of professional soldiers with superior discipline and fighting spirit, and they are well known on the European battlefield for their near-invincibility in combat. The tercio formation is feared by enemy troops because of the legendary determination of its soldiers in combat; its reputation was fully established at the Battle of Pavia in 1525, in which the French king François I was captured by the Spaniards.

The soldiers of a tercio are armed with an assortment of weapons to deal with any enemy they encountered on the battlefield. In the earliest days of the formation approximately 1,500 of them were equipped with pikes, 1,000 kept the ancient short sword and javelin armament, and the remaining 500 were armed with arquebuses of the best and most portable type; the javelins were subsequently replaced with musketeers, though a number of soldiers carrying swords-and-bucklers continue to occupy the ranks of the pikemen, as they are effective during hand-to-hand melee against opposing pikemen. In battle the pikemen form squares with the sword-and-buckler men inside, the musketeers forming close lines along the edges of the square, and the arquebusiers, together with field artillery, assuming positions in between the squares to gain the best angles of fire on any enemies approaching the tercio square.

In front of the square formations the soliders dig ditches or other fortifications to further disrupt a cavalry charge, against which they are essentially invulnerable. Even in battle against an opposing force of pikemen, the tercio had the upper hand in terms of ranged firepower with the musketeers and arquebusiers causing devastating casualties amongst the tightly packed pikemen as well as the fact that a pikeman, needing both hands to wield his pike, is essentially defenseless against the tercio swordsmen.


Le Ballet de l'Acier Black_Vulmea