Welcome to part one of an unknown number where I will be looking at some of the common types of armor worn during Medieval England and, perhaps, Medieval Iceland. To start things off, I am looking at one of the most basic pieces of armor: leather armor. While there are many other parts of armor that were worn, for the purpose of this series I am solely looking at, and considering, the body armor. In the future I may look at shields, helmets, bracers, and many others.
When you think of the medieval times, odds are you think of a suit of metal armor. Many knights and lords would certainly go around armed in that manner, but not everyone could afford a suit, much less a shirt, of chain mail or plate mail to provide defense. So a poorer person might wear either leather armor, or else a gambeson (more on that next week!) when they went into battle. Some protection would be better than nothing, right?
Leather armor was made from boiled hides, a process which would harden them to where they could be worn and offer protection, while still allowing a reasonable amount of movability. A style of combat similar to modern fencing would likely have been an ideal situation to wear this armor, as it would allow agile motions due to flexibility and the light weight.

Image from wulflund.com
The primary purpose of armor was to stop, or deflect, the blows from the opponent. As the weaponry of an era advanced to penetrate a certain armor type, the armor would upgrade in ways to provide that protection. Unfortunately, leather armor would most likely have proven to be ineffective at stopping many of the attacks during this time. It would likely have been made from the skin of a sheep or goat, but an animal with a thicker hide (such as a bull) would have made a better layer of protection. In order to really provide the needed protection, the wearer would need several layers to deflect the blow from a sword, axe, or lance. Even a bludgeon weapon would be effective against a single layer of leather armor. This makes it unlikely that anyone who expected to be involved in serious warfare would wear leather armor, unless in layers or reinforced with strips of metal or some other device to improve its protective abilities.
This is not to say that leather armor was without its uses. There are some people who may have found it to be effective in certain situations. The common man or woman who sought some inexpensive layer of protection in the streets could have donned the leather armor. Seafaring men would have made use of leather armor, as chain or plate mail armor would prove too heavy to swim with should they fall overboard. So while mounted troops and infantry may have passed over the leather armor, there were certainly places where it might prove useful.

Image from behance.net
But, as you will see next week, the gambeson might have been the go-to armor of choice for those who were considering saving on price, or even those who wanted protection from projectiles and blades in combat.