many scholars think mail was invented by ancient celts about the 3rd century bc. at that time their iron work was probably the best in europe. the romans quickly adopted it for their own army. a shirt of mail armour weighed about . after a battle it was common practice to strip weapons and armour from the dead. vikings were known to wear mail armor whenever they could get their hands on it. mail was expensive, time-consuming to make, and required a supply of iron. it became more expensive as improvements were made in materials and workmanship. mail armour was in use in europe until the 15th century.