Chain mail use in the ancient world

Often when I am looking for images of ancient people or events I encounter art, usually medieval, with ancient people dressed anachronistically in medieval clothing.  This morning, however, I happened across a wall painting from a synagogue in Dura Europos dated to 250 CE clearly depicting soldiers in chain mail at the battle of Eben Ezer between the Israelites and the Philistines as retold in the Book of Samuel.  The Philistines inhabited the coast of Canaan from the 12th century BCE until 604 BCE when they were destroyed by King Nebuchadnezzar II of Babylonia. I was pretty sure that was before chain mail was used for body armor.  Just to be sure, though, I looked it up and as I suspected, chain mail did not become common military armor until the 3rd century BCE. 

The Romans adopted mail after observing its use by the Celts. The earliest depiction of Roman mail armor was found on the Aemilius Paulus Monument in Delphi.  The mail shirt was long and completely covered the thighs.  Such long mail shirts are also depicted on the Altar of Domitius and on defeated Galatians on a weapons relief from Pergamon dated to the 2nd century BCE. These shirts also featured, according to depictions, broad epaulets to provide added protection for the shoulders although this aspect has not yet been found in the archaeological record. The shirts were fastened by leather straps, then later by hooks.  During the Flavian period, S-shaped bronze fastening clasps were introduced.

By the 2nd and 3rd centuries CE, a T-shirt-like mail garment was introduced that could be slipped over the head, without fasteners or shoulder doubling, although  examples have been found that still had a sheet metal fastener in the chest area.  It was suggested these were included simply for decoration but this has been considered refuted by current scholars.  

Although various scholars have suggested mail was worn by both citizen legionaries and auxiliary soldiers, Trajan's column depicts legionaries in segmented armor while auxiliaries are shown wearing short mail shirts with a lower serrated edge.  However, this type of mail has not been found in the archaeological record.

Image: Fresco from a synagogue in Dura Europos dated to the 2nd century CE depicting the battle of Eben Ezer between the Israelites and the Philistines courtesy of Wikimedia Commons contributor Marysas.