The Use and Effectiveness of Artillery Fire
Initially, cannons were used primarily against fortifications such as castle walls. The use of artillery fire directly against people was even considered sinful. However, as early as the Battle of Crécy in 1346, the English employed cannons in a field battle against French troops.
Solid shot was highly effective against wooden fortifications. Wooden defenses could also be set on fire using red-hot projectiles or carcasses (incendiary shells). Stone walls, however, required the use of heavy siege artillery. In breaching masonry fortifications, forged iron shot was sometimes used in addition to cast-iron projectiles because of its harder surface. Cannons were positioned as close to the walls as possible, sometimes only 10–20 meters away. As the effectiveness of small arms increased, however, it became impossible to bring artillery so close to enemy fortifications.
The inaccuracy of early artillery made breaching walls difficult. It was hard to hit the same spot repeatedly. Nevertheless, even inaccurate bombardment often caused masonry fortifications to collapse because continuous firing critically weakened the mortar joints, even if the stones themselves did not always break. Fortification walls were often constructed with earth fill behind the stone facing, and when a section of wall failed, the fill would spill out through the breach.
The Siege of Narva
The Swedish capture of Narva in 1581 under the command of Pontus De la Gardie involved extensive use of artillery to breach the fortress walls. The besieging forces brought with them 32 different artillery pieces, including 22 heavy siege guns. In addition, mortars firing incendiary ammunition, fire-arrow launchers, and wagon-mounted artillery pieces were employed.
The consumption of ammunition was carefully recorded. During a period of two days, the heavy artillery fired approximately 4,700 cannonballs. The lighter artillery fired around 300 rounds. Fire was directed at both the upper and lower sections of the three-meter-thick walls, successfully creating breaches. Through these openings, infantry forces entered the city on 6 September 1581.
Use Against Manpower
Artillery quickly expanded from its original role in fortress and siege warfare to use in field battles. Especially in the early period, the noise and shock of cannon fire alone could be sufficient to repel attacks, particularly those conducted by cavalry.
Engagement ranges were generally limited to a few hundred meters at most. Against troops, artillery typically fired direct, sweeping fire so that the solid projectile would ricochet as many times as possible and cause maximum destruction. Infantry and cavalry usually fought in dense formations, where bouncing cannonballs inflicted heavy casualties.
Explosive shells were fired from high-angle weapons, and their use became increasingly common with the wider adoption of howitzers, particularly during the 18th century. As infantry formations became somewhat less densely packed than before, explosive ammunition often proved more effective than solid shot.
At close range, canister and grapeshot ammunition were fired, proving highly effective against attacking infantry and cavalry.