Factors of Medieval Armor development
Armor changed, evolved and improved over the medieval period and there are a few factors that had a tremendous impact on this evolution.
The development of different types, and more effective weapons: Weapons such as swords, spears, daggers and polearms all changed over the centuries, in part to achieve effectiveness against armor. The longbow and crossbow were very effective against varying armor types and new armor had to be developed to counter these weapons. This changing and evolving between weapons and armor were what could be called an arms race - weapons would improve then armor would improve then weapons had to improve and so on.
Developments in metal working skills - as we moved out of the bronze age and into the iron age the new ways of working with metals made stronger armor and gave armies technologies to make more effective armor.
Changing philosophies and cultures - these things also had a big impact on how armor changed.
Gunpowder eventually put an end to armor.
Armor before the Medieval Period
There are two major lines of armor that lead up to the armor in Europe through the Medieval Period. The first line is the classical line that came out of the Mycenaean (Alexander the Great), Greek and Roman traditions. The major materials that armor was made from included Bronze and Iron.
The second line came out of the Celtic and Teutonic people. This is called the Barbarian armor line. The armor made in this line was predominantly leather and mail.
The dominance of Chainmail through most of the medieval period
Out of all the various armor types chain mail (also known as ring mail) was the most successful and it lasted the longest. Earliest versions of this type of armor date back to the first century and this mail was in use in different variations all the way through the medieval period and beyond to the 17 th century. It was called chain mail or ring mail because it was made of a series of small rings that were interlocked together. This means of assembly was very effective against slicing and stabbing weapons and normal arrows. It was also very complex to make and a chainmail chest piece (often called a hauberk) could be composed of thousands of these little rings. (The picture shows a knight in complete chainmail with a surcoat over it)
Chain Mail - It was in use in various forms throughout the whole medieval period in a variety of capacities. For many centuries is was very effective. But the brunt of its effectiveness was against slashing weapons. The rings that composed the mail were effective at defeating slashing weapons but were not effective against the brunt force blow of weapons such as hammers and maces.
Want to watch a video on how to make chainmail? I have one on my youtube channel here. How to Make Chainmail
Over the centuries of the medieval period this deficiency was minimized by added a variety of other materials either under or over the chain mail hauberk. These could be a leather jerkin or padded gambeson under the mail or a coat or plates and a surcoat over the mail. This could get very cumbersome and while adding extra layers of padding and protection could reduce concussive damage it still didn't keep pace with the development of weapons.
In the 13 th century the mail become less and less effective, particularly because of the use of crossbows and better weapons. Armorers moved in the direction of adding various pieces of plate either under the mail or over the mail. These were just parts like chest plates or elbow guards. This was a move toward plate armor.
A development in armor was the coat of plates which lasted roughly through the 14th century.
After 1350 the use of solid breastplates came into more use. They were typically made of a solid plate in the front and a solid plate in the back called a backplate. Iron breastplates appeared as early as 1190.
The Transition to Plate Mail
The most important development after the common use of the breastplate was the addition of more plate armor on various body parts. These included vambraces over the arms, greaves for the lower legs and various other partial plates for shoulders, elbows and knees. (Drawing shows this transition with full mail armor and the addition of some plate armor on arms and legs)
Eventually these all evolved into the complete set of plate armor that we think of when we think of a knight in armor. In this armor every part of a knight's body was covered with plate armor. And these developments of additional protection also had sub developments. A good example of this is the demi-greaves which covered only the front part of the lower leg. These developed into closed greaves which went all the way around the lower leg.
The 15 th Century as the zenith of Platemail suits of Armor
The 15 th century was the pinnacle of medieval armor and it all revolved around the knights complete set of plate armor. In the beginning of the century the art and craft of making complete plate armor sets developed into two different schools: The Italian and the German. Toward the end of the 15 th century and beginning of the 16 th century these two schools diverged into what is considered to be the pinnacle of armor making: The Maximilian.
It is during this century that armor also morphed into three different types of armors - Field armor (for Battle) , Ceremonial armor (for ceremonies and good looks) and jousting armor for the knightly competitions. Each type of armor was specifically designed for its use. Battle armor was designed for maximum mobility with optimal protection, ceremonial armor was made to look great and to impress. It was often detailed with gold and silver. And Jousting armor was designed for the specific requirements of the joust which might include an overly large and strong pauldron to deflect an enemy's lance or special braces to support the weight of one's own lance.
Helmets - Helmets also underwent many changes during the medieval period and a lot of this was influenced by the ability to work with metal and better understanding of what protected better in combat.
Early helmets were typically flat and they developed toward more round and curved in shape because a curved shape would deflect a blow rather than take the full brunt. And in the latest periods the helmets were multiple pieces riveted together and had moving parts like a visor.
Shields - These also changed as other components of armor and weapons changed. In the early centuries of the medieval period they were large and round. As the centuries progressed the got smaller and triangular in shape. I have more information about medieval shields and how they developed and changed here: The Medieval Shield
Metal Working skills throughout the medieval period
The early armor was made with leather, iron, bronze or other hard materials. Steel was developed but only saw limited use because it was difficult to make and tended to be brittle. In the later centuries techniques were developed so plates of armor had carbon added to just the outer surfaces of them. This created a very hard outer surface yet with the softer inner surface of iron there was still some flexibility.
History of Medieval Armor Timeline