Heavy infantry

Heavy infantry consisted of heavily armed and armoured infantrymen who were trained to mount frontal assaults and/or anchor the defensive center of a battle line.

Heavy infantry typically made use of dense battlefield formations, such as shield wall or phalanx, multiplying their effective weight of arms with force concentration.

After the fall of Rome, heavy infantry declined in Europe but returned to dominance in the Late Middle Ages with Swiss pikemen and German Landsknechts.

With the rise of firearms during early modern warfare, dense formations became increasingly hazardous, and heavy armours were either ineffective or too cumbersome to be tactically useful.

Post-Alexander Hellenistic states such as Macedonia, Seleucid Persia, and Ptolemaic Egypt would employ more heavily armored phalangites, as well as their own variation of elite units such as the silver shields.

Some of the more heavily armed Celts wore mail armour and "Galea" type helmets, and threw javelins in battle; all of these elements were later adopted by the Romans.

Incidentally, the hastati were originally armed with this weapon, which gave them their name, but the hasta were eventually abandoned as Rome switched from a Greek-style hoplite phalanx to the manipular system.

Rome's use of heavy infantry and a general lack of major cavalry forces meant they were stronger in pitched battle but more vulnerable to ambushes.

After the late 2nd century BCE, the three-lined maniples were replaced in favor of a single type of heavy infantry, the legionary, all equipped in nearly identical fashion to hastati and principes.

The weapons and armor of the heavy infantry of Goguryeo were considered the best in quality because of the advanced technological improvements made in steel and iron production in Korea.

Meticulous development and implementation of efficient swordsmanship and martial arts, tactics, and technology allowed Goguryeo armies to remain virtually undefeated during the height of its existence.

One additional factor that lessened heavy cavalry's role on the battlefield, despite innovations such as the stirrup, were the inventions of the longbow and the crossbow after the eleventh century.