Breastplate armor was a common part of the late medieval armor in Europe. It evolved significantly over the course of the Middle Ages and took many different forms.
Initially, it took the form of a cuirass and was alternatively used as a part of the surcoat, often sewn into the surcoat garment of the knight. Later, more solid and single-pieced breastplates came into fashion in Europe.
By the 14th and 15th centuries, breastplates had become a permanent part of battlefield armor. The breastplate was one of the most vital pieces of medieval armor while its use lasted since it shielded the wearer from the main thrust and direction of the enemy’s weapons. It was a popular part of the armor all the way until the Napoleonic Wars in the 19th century.
Although the breastplate was commonly used in ancient Greek culture, it was largely abandoned as a piece of body armor in the early period of the medieval ages.
This period was noted by the widespread use of chainmail armor among European knights. However, by the 13th century, breastplates came back into use.
By this time, it was often sewn into the padded surcoat of a knight, giving the knight more flexibility and freedom of movement compared to the wearer of a single-piece breastplate.
By the 14th century, single-piece breastplates were being used by European armies. The breastplate is among the few pieces of body armor which survived in different forms all the way into the modern age, being the precursor to the modern-day bullet-proof vests.
The early form of the medieval breastplate was a cuirass that covered the front of the wearer’s torso. When used in conjunction with the surcoat, the breastplate comprised of several disjointed pieces which when sewed into the surcoat gave the semblance of a single piece of armor.
By the 14th century, the breastplate evolved into a piece of armor that was made from a single piece of armor and constructed from a solid metal such as iron or steel.
The edges of this form of the breastplate were folded out for the wearer’s protection against bruises and the thickness of the plate ranged from 1mm to 2.5mm.
While the design of the 14th-century breastplate covered only the top part of the torso of the wearer, it evolved in the 15th century to cover the upper and lower torso, giving the wearer additional protection.
This evolution also turned the breastplate into a two-piece armor, with the two plates covering the top and bottom parts of the torso and often overlapping.
The Breastplate was initially less favored compared to chainmail armor in the early Middle Ages. This was primarily because chainmail carried less weight and offered more freedom of movement. However, by the late Middle Ages, the breastplate was a standard part of medieval plate armor.
Despite being heavy, the breastplate was very effective against piercing weapons as well as heavy blows, deflecting most of the enemy’s strikes from the polished surface.
A minor drawback of the breastplate was that under hot weather conditions, it could heat up rather quickly and become highly uncomfortable to wear. But compared to battlefield advantages, this was mostly endured by the knights.