Shield A shield is a type of personal armor , meant to intercept attacks , either by stopping projectiles such as arrow s or redirecting a hit from a sword , mace , battle axe or similar weapon to the side of the shield - bearer . Shields vary greatly in size , ranging from large panels that protect the user ' s entire body to small models ( such as the buckler ) that were intended for hand - to - hand - combat use . Shields also vary a great deal in thickness ; whereas some shields were made of relatively deep , absorbent , wooden planking to protect soldiers from the impact of spear s and crossbow bolts , others were thinner and lighter and designed mainly for deflecting blade strikes . In prehistory and during the era of the earliest civilizations , shields were made of wood , animal hide , woven reeds or wicker . In classical antiquity , the Migration Period and the Middle Ages , they were normally constructed of poplar , lime or another split - resistant timber , covered in some instances with a material such as leather or rawhide and often reinforced with a metal boss , rim or banding . They were carried by foot soldiers , knights and cavalry . Depending on time and place , shields could be round , oval , square , rectangular , triangular , bilobial or scalloped . Sometimes they took on the form of kites or flatirons , or had rounded tops on a rectangular base with perhaps an eyehole . The shield was held by a central grip or by straps which went over or around the user ' s arm . Often shields were decorated with a painted pattern or an animal representation and these designs developed into systematized heraldic devices during the High Middle Ages for purposes of battlefield identification . Even after the introduction of gunpowder and firearms to the battlefield , shields continued to be used by certain groups . In the 18th century , for example , Scottish Highland fighters liked to wield small shields ( known as a targe ) , and as late as the 19th century , some non - industrialized peoples employed them ( such as Zulu warriors ) when waging war . In the 20th and 21st century , shields have been used by military and police units that specialize in anti - terrorist actions , hostage rescue , riot control and siege - breaking . The modern term usually refers to a device that is held in the hand or attached to the arm , as opposed to an armored suit or a bullet - proof vest . Shields are also sometimes mounted on vehicle - mounted weapons to protect the operator . Prehistory and antiquity . The oldest form of shield was a protection device designed to block attacks by hand weapon s , such as swords , axes and maces , or ranged weapon sling - stones and arrows . Shields have varied greatly in construction over time and place . Sometimes shields were made of metal , but wood or animal hide construction was much more common ; wicker and even turtle shells have been used . Many surviving examples of metal shields are generally felt to be ceremonial rather than practical , for example the Yetholm - type shields of the Bronze Age or the Iron Age Battersea shield . The shield was used to make the Greek Phalanx formation . Size and weight varied greatly . Lightly armored warriors relying on speed and surprise would generally carry light shields ( " pelte " ) that were either small or thin . Heavy troops might be equipped with robust shields that could cover 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 . During the 14th - 13th century BC , the Sards or Shardana , working as mercenaries for the Egyptian pharaoh Ramses II , utilized either large or small round shields against the Hittites . The Mycenaean Greeks used two types of shields : the " figure - of - eight " shield and a rectangular " tower " shield . These shields were made primarily from a wicker frame and then reinforced with leather . Covering the body from head to foot , the figure - of - eight and tower shield offered most of the warriors body a good deal of protection in man to man combat . The Ancient Greek hoplites used a round , bowl - shaped wooden shield that was reinforced with bronze and called an aspis . Another name for this type of shield is a hoplon . The hoplon shield inspired the name for hoplite soldiers . The hoplon was also the longest lasting and most famous and influential of all of the ancient Greek shields . The Spartans used the aspis to create the Greek Phalanx formation . Their shields offered protection not only for themselves but for their comrades to their left and right . Examples of Germanic wooden shields c350 BC - 500 AD survive from weapons sacrifice s in Danish bogs . The heavily armored Roman legionaries carried large shields ( " scuta " ) that could provide far more protection , but made swift movement a little more difficult . The " scutum " originally had an oval shape , but gradually the curved tops and sides were cut to produce the familiar rectangular shape most commonly seen in the early Imperial legions . Famously , the Romans used their shields to create a tortoise - like formation called a " testudo " in which entire groups of soldiers would be enclosed in an armoured box to provide protection against missiles . Many ancient shield designs featured incuts of one sort of another . This was done to accommodate the shaft of a spear , thus facilitating tactics requiring the soldiers to stand close together forming a wall of shields . Middle Ages . In the early European Middle Ages , simple round shields made from linden - wood wood covered on both sides by leather were typical . Over time , these were displaced by the kite shield , which was rounded at the top and tapered at the bottom . This gave some protection to the user ' s legs , without adding too much to the total weight of the shield . Kite shields were commonly used by cavalry as well . As body armour improved , knight ' s shields became smaller , leading to the familiar heater shield style . Both kite and heater style shields were made of several layers of laminated wood , with a gentle curve in cross section . The heater style inspired the shape of the symbolic heraldic shield that is still used today . Eventually , 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 pavise s , which were propped up on stands , were used by medieval crossbow men who needed protection while reloading . In time , some armoured foot knights gave up shields entirely in favour of mobility and two - handed weapons . Other knights and common soldiers adopted the buckler ( origin of the term " swashbuckler " ) . The buckler is a small round shield , typically between 8 and 16 inches ( 20 - 40 centimeters ) in diameter . The buckler was one of very few types of shield that were usually made of metal . Small and light , the buckler was easily carried by being hung from a belt ; it gave little protection from missiles and was reserved for hand - to - hand combat . The buckler ' s use began in the Middle Ages and continued well into the 16th Century . In Italy , the targa , parma and rotella were utilized by common people , fencers and even knights . 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 . During the 19th Century , non - industrial cultures with little access to guns were still using war shields . Zulu warriors carried large lightweight shields made from a single ox hide supported by a wooden spine , these were called Ishlangu . This was used in combination with a short spear ( assegai ) and / or club . Although the size of shield would vary due to personal preference and role , most were thin compared to common belief ( a misconception aided by the depiction of heavy shields in films ) . When used in fighting , shields were most effective when used to cause glancing blows . By deflecting a sword blow to the side , rather than blocking it head on , the attacker could be rendered open to a counterattack . This technique allowed the shield to be made lighter and more easily wielded , while reducing the amount of energy and risk of injury posed to the shield - bearer . Modern era . Law enforcement shields . Shields for protection from armed attack are still used by many police forces around the world . These modern shields are usually intended for two broadly distinct purposes . The first type , riot shield s , are used for riot control and can be made from metal or polymers such as polycarbonate Lexan or Makrolon or boPET Mylar . These typically offer protection from relatively large and low velocity projectiles , such as rocks and bottles , as well as blows from fists or clubs . Synthetic riot shields are normally transparent , allowing full use of the shield without obstructing vision . Similarly , metal riot shields often have a small window at eye level for this purpose . These riot shields are most commonly used to block and push back crowds when the users stand in a " wall " to block protesters , and to protect against shrapnel , projectiles , molotov cocktails , and during hand - to - hand combat . The second type of modern police shield is the bullet - resistant tactical shield . These shields are typically manufactured from advanced synthetics such as kevlar and are designed to be bulletproof , or at least bullet resistant . Two types of shields are available . 1 . Light weight level IIIA shields that stop hand guns and submachine guns . 2 . Heavy Level III and IV shields that stop rifle rounds . Tactical shields often have a firing port so that the officer holding the shield can fire a weapon while being protected by the shield , and they often have a bulletproof glass viewing port . They are typically employed by specialist police , such as SWAT teams in high risk entry and siege scenarios , such as hostage rescue and breaching gang compounds , as well as in antiterrorism operations . Tactical shields often have a large signs stating " POLICE " ( or the name of a force , such as " US MARSHALS " ) to indicate that the user is a law enforcement officer . Gun shields . With the widespread use of machine guns in World War I and in subsequent conflicts , battlegrounds were swept with automatic weapons fire . While soldiers who are in foxholes or trenches are protected from this fire , soldiers who are manning mounted machine guns were vulnerable to being hit . Since WW I , there have been a variety of attempts to install armored gun shields on tripod - mounted machine guns or vehicle - mounted weapons to protect machine gunners . Transportation devices with mounted guns that may have gun shields to protect the gunner include jeeps , Humvees , armored cars , and boats . Non - martial applications . Many non - martial devices also employ shielding of a kind — not usually a single device worn on an arm but various protective plates or other insulation positioned where needed . Space craft have heat shields to ensure a safe re - entry . Electronics uses shielding to reduce electrical noise and crosstalk between signals . Better - quality patch cables used in audio and electronic music have shielding to reduce interference and noise . People and systems that must work in the presence of ionizing radiation ( X - rays ) such as dentists , hospital technicians , and patients undergoing X - rays are protected with lead shielding clothing . Emblems that resemble heraldic shields are also called shields . Movie studio Warner Bros . uses a shield emblazoned with WB as its logo . The Looney Tunes cartoons , released through Warner Bros . , open with the WB shield zooming through concentric circle s .