Shield

A shield is a protective device, meant to intercept attacks. As opposed to armour and other similar protective devices, a shield is usually hand-held.

Production
Shield constructions have varied greatly over time and place. Sometimes shields were made of metal, but wood or animal hide construction was much more common; today metal or synthetic materials like Lexan or Kevlar are used.

In the middle ages, shields were made of several layers of laminated wood, with a gentle curve in cross section.

History
The shield as protection against hand weapons (such as swords, axes and maces) or missiles (like spears and arrows) is known at least since the bronze age.

Size and weight varied greatly, lightly armored warriors relying on speed and surprise would generally carry light shields that were either small or thin. Heavy troops might be equipped with large heavy shields that could protect most of the body. Many had a strap called a guige that allowed it to be slung over the user's back when not in use or on horseback.

The heavily armored Roman legionaries carried large, heavy shields (scuta) that could provide far more protection, but made swift movement a little more difficult.

In the early European Middle Ages, kite shields were commonly used; these were rounded at the top and tapered at the bottom. They were easily used on horseback and allowed easier leg movement when dismounted. As personal body armour improved, knight's shields became smaller, leading to the familiar heater shield style. Specialised shapes were developed such as the bouche — which had a lance rest cut into the upper corner of the lance side, to help guide it in combat or tournament.

Free standing shields called pavises were used by medieval crossbowmen who needed protection while reloading.

In time, some armoured foot knights gave up shields entirely in favour of mobility and two-handed weapons or adopted the buckler, a small round shield which gave little protection against missiles and was reserved for hand-to-hand combat. The buckler continued in use well into the 16th Century.

The development of plate armour made shields less and less common as plate armour eliminated the need for a shield. Lightly armoured troops continued to use shields after men-at-arms and knights ceased to use them. Shields continued in use even after gunpowder powered weapons made them essentially obsolete on the battlefield. In the 18th Century, the Scottish clans used a small, round shield called a targe that was partially effective against the firearms of the time although it was arguably more often used against British infantry bayonets and cavalry swords in close-in fighting.

In the 19th Century, non-industrial cultures with little access to guns were still using shields. Zulu warriors carried large lightweight shields made from a single ox hide supported by a wooden spine called Ishlangu.

Shields for protection from armed attack are still used by many police forces around the world. There are two distinct shield types in use, for different pupose each:

Riot control shields are made from metal or synthetics and typically offer protection from relatively large and low velocity projectiles, such as rocks, bottles, shrapnel, molotov cocktails, and during hand-to-hand combat as well as blows from fists or clubs. Synthetic riot shields are normally transparent while metal riot shields often have a small window at eye level for this purpose.

The second type of modern police shield is typically manufactured from advanced synthetics such as kevlar and are designed to be bulletproof, or at least bullet resistant. These are typically employed by specialist police, such as SWAT teams, in high risk entry and siege scenarios, but are also used on a daily basis in many areas of the US.