Image from Bernd Helfert
Body armour developed early as protective suits made of such materials as leather, shells, wood, and basketwork, later supplemented by metal and synthetic materials.
Armour was made specifically for war, was often very costly, and could be an index of social status (e.g. Greek hoplite, Japanese samurai, European nobleman/knight). With the rise of science increased mobility and firearms made personal armour obsolete, although the atomic and information age saw its re-introduction in composite materials, such as kevlar, arachnoweave, and tetracarbon, for soldiers, police, and even civilians. The next development was the powered exoskeleton, which developed into true combat mecha by the incorporation of AI expert systems, advanced weapons and efficient power storage systems.
The other extreme saw various forms of nanoskin, intelligent and reactive micro- and nano-armour, tending towards lightness, self-repair and stealth rather than bulk. Body-modification and cyborgisation has also meant that armour can be made integral to the overall body, rather than something to be put on and taken off.