In little more than two decades Alexander the Great of Macedon (356-323 BCE) conquered by military force nearly the entirety of the known world. Despite the fact that he led one of the most successful armies of all time, surprisingly little is understood about the main type of body armor that apparently both Alexander and many of his men wore.
This was the linothorax, a type of body armor created by laminating together layers of linen. While we know quite a lot about other types of ancient armor made from metal because specimens have been excavated, the linothorax remains something of a mystery since, due to the perishable nature of its material, no examples have survived. Today, the linothorax is only known through about two dozen descriptions in ancient literary sources and approximately 700 visual images in mosaics, vase paintings, and sculptures. Despite the doubts of some modern scholars regarding how something made of cloth could have provided effective protection to its wearer, the linothorax clearly thrived as a form of body protection for nearly 1,000 years, and was used by a wide variety of ancient Mediterranean civilizations.
The video and article linked below describe an experiment conducted at the University of Wisconsin to replicate the linothorax and test its protective properties.