Chainmail
Overview
 
Mail is a type of armour
Armour
Armour or armor is protective covering used to prevent damage from being inflicted to an object, individual or a vehicle through use of direct contact weapons or projectiles, usually during combat, or from damage caused by a potentially dangerous environment or action...

 consisting of small metal rings linked together in a pattern to form a mesh.
Mail was a highly successful type of armour and was used by nearly every metalworking culture.
Mail first appeared some time after 300 BC. Its invention is credited to the Celts. It may have been inspired by the much earlier scale armour
Scale armour
Scale armour is an early form of armour sometimes erroneously called scale mail consisting of many individual small armour scales of various shapes attached to each other and to a backing of cloth or leather in overlapping rows. Scale armour was worn by warriors of many different cultures as well...

. From the adoption by the Romans
Roman Republic
The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and...

 of Celtic mail to its decline in the 17th and 18th centuries the history of mail was one of proliferation.
 
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