Starting in the 14th century

Infantry were gaining the upper hand over armored horsemen on the battlefields of medieval Europe

Archers and ranged troops were able to bring them down at distance and mass

Formations of pikemen and halberdiers could stop them dead in their tracks

The Swiss infantry of the time with their well disciplined squares of pikemen showed that they could consistently defeat large armies

containing heavy medieval horsemen

Tacticians of the day began to experiment with the most effective way to deploy their infantry as their importance on the field of battle

grew over the years

The integration of pikemen and arquebusiers into a unified fighting force

Was a major issue that military leaders were grappling with by the end of the 15th century

it was the Spanish armed forces who pioneered the new methods of infantry fighting and they created a new type of

organizational unit the Tercio

The Spanish would improve the effect of the Swiss Square by adding the firepower of the arquebus and by the first part of the 16th century

They were transformed into the most formidable military force of its age

They were the first fighting force to efficiently mix pikes and firearms

Literally meaning "third". They were originally designed to be composed of one-third pikemen, one-third swordsmen, and one-third gunmen

Tercio companies dominated European battlefields in the 16th century and the first half of the 17th century and are seen by

historians as a major development of early modern combined arms warfare

The size of tercios varied between specific forces but also over time

With a typical unit having around 1,500 men, but up to 3,000 were deployed in some situations

They were then organized into companies of 250 to 300 men each

Tercios had extremely affected leadership as they were led by a maestre de campo who was in charge of the entire unit

They were generally well respected by their troops as they usually came from the ranks of the tercio itself

The maestre de campo was appointed by the king but still had to prove their ability in battle before given leadership of the unit

Each company was led by captain and the maestre de campo and the captain's all had

experienced second in commands ready to take over their duties if needed as

a standing army these soldiers in the Tercios were

Experienced combat veterans due to their constant deployment around the world and service of the Spanish Empire

They were either on campaign quelling insurrections or pacifying enemy territories

They had to be trained in all types of warfare including siege craft ship-to-ship warfare and even amphibious assaults

Another factor that gave Tercios the edge against others was that typically the core of Spanish armies were formed by Spanish subjects

Who were renowned for their discipline cohesiveness and professionalism

Other European powers who had adopted the Tercio formation

normally used foreign soldiers or mercenaries who often didn't match the Spanish in their fighting abilities or motivation

Logistically, the Tercios had a relatively light footprint allowing them to move all over Europe fairly quickly

Much of their success is in fact due to their mobility at a strategic level as an infantry formation

they did not have to worry about supplies for horses, and they operated separately from artillery units and

only took light field guns with them as

Long as they had powder and shot

The Tercio could live off the land and be ready for battle at the end of a long march

Tactically what also made them so effective was that they combined traditional warfare strategy with the newest weapons of the time

The pikemen would protect the other soldiers within the unit from enemy cavalry or infantry charges

These swordsmen would be placed near the pikemen in case the unit was reached and close range combat was needed

The gunmen were positioned to attack in harass hostile units

Also, they were used to degrade the effectiveness of enemy pike squares

diminishing their capacity to resist offensive attacks as

The firearm rose and prominence the use of swordsmen declined and were phased out in the coming centuries

Eventually Spanish commanders also solved major problems that plagued the effectiveness of using gunmen in battlefield formations

Both the arquebus and the later muskets were highly inaccurate and only massed volley fire could be effective

Also the rates of fire were agonizingly slow as getting off one round per minute was considered a good rate

Gunners simply could not shoot accurately enough and fast enough to stop a charge of enemy infantry

to combat this issue Spanish commanders imposed strict fire discipline

Gunmen were formed up in depth and trained not to fire without orders

The procedure was for the first rank to deliver a single masked volley on command and then retire to the rear to reload

The second rank would then step forward aim fire on the order and retire and so on as the tercio could deliver volley after volley

against an advancing formation of enemy troops

By 1590 the spanish were able to maintain a constant rate of fire by rotating ranks of gunmen through one another

In battle the Terios were generally more maneuverable and had more extensive skirmishing abilities than other pike and shot formations

Their companies could maneuver independently in battle with later versions of the Tercios having up to four blocks of mangas

Mangas were a detachment of 100 to 400 men that were more mobile than the regular Tercio formations

They would detach themselves from the main Tercio force to harass enemies and keep them engaged in combat

mobile formations of Spanish arquebusiers reorganized to the flanks were decisive at the Battle of Pavia in

1525 against the kingdom of France

the highly effective Spanish gunman caused tremendous casualties to the French forces

Which were virtually annihilated during the battle the victory led to the rise of Spanish Habsburg domination in Italy

Even in defeat the skill of the Spanish tercio won them Fame and admiration throughout Europe

During the siege of Castelnuovo in 1539

About four thousand Spanish defenders were attacked by fifty thousand soldiers of the invading Ottoman Empire

After weeks of valiant resistance, the walled town was eventually taken by the Ottomans

However, the Ottomans suffered 20,000 deaths in the assault while the Spanish lost almost everyone in the heroic defense against all odds

The difference between Spanish tercios and other armies using the same tactics was highlighted at the Battle of Nordlingen against Swedish

led Protestant forces in 1634 during the 30 Years War the

30 Years War started as a struggle between Catholic and Protestant States

But eventually evolved over the years into a general conflict between the great European powers

At the time the Swedish army was considered one of the strongest if not the strongest and most effective in Europe

Also, they had already defeated other pike and shot European powers in numerous battles

However, it was the highly trained Spanish troops that made the difference between victory and defeat

During the engagement the Spanish would use a special tactic to reduce the effect of the powerful Swedish gunfire

When a Spanish officer would see the Swedish prepare to fire he ordered his men to kneel and let the bullets pass over their heads

And then counter fire a volley

The tercios withstood relentless assaults and stood their ground against the Swedish led forces

With successful counter-attacks leading them to victory

By the end of the two-day battle the Swedish army was completely routed

Although only a small part of the overall Roman Catholic army, the Spanish tercios were a decisive factor in the battle

Extraordinary unit cohesion of the Spanish tercio is another key reason for their effectiveness on the battlefield

They had a unique ability to take substantial combat losses and yet maintain unit integrity and continue fighting

At the time it was simply unheard of for any unit to take heavy losses in an open field and not flee or surrender

This can be seen at the Battle of Rocroi against the French in

1643 in which the dominance of the Spanish Tercio was finally shattered in battle

The French skillfully outmaneuvered the Spanish cavalry and artillery and began withering attacks on the enemy infantry

Allied nations Pike and shot formations broke under the attacks and fled the field, but the Spanish tercios continued fighting

Even though the situation was dire

reinforcements were expected

So the Tercios has fought on taking mounting losses until acceptable terms were offered

In the end their battlefield casualties were over 60% but the Spanish were allowed to orderly withdraw from the field with their standards and weapons

Even then the defeat was mostly due to the collapse of the supporting cavalry

Rather than the failure of the tercios themselves who had fought valiantly in the battle

Tercios continued to win important battles for a time even after the 30 Years War, but they were greatly modified from their older forms

By then improvements in field artillery and firearms had given the new linear combat style a decided advantage

pioneered earlier by the Dutch

The later 17th century tercios adopted so much of the linear styles organization and tactics

They had little resemblance to their classic forms of the previous century

By the beginning of the 18th century the Spanish Tercios were transformed into regiments

The Spanish Tercio was a major success on the battlefield for almost a century and a half due to a combination of factors

This can be seen through its ability to coordinate weapons into battlefield formations, a strict combat discipline,

Good training, a strong fighting spirit, an experienced and skilled commanders

All of these abilities together was the very definition of a professional army

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