Old becomes new again: Trench armour and weapons in WWI

The Great War is known as one of the first mass industrial conflicts, and set the tone for warfare in the twentieth century.  Traditional cavalry unites became obsolete and as the conflict settled into a static front in the west it became a war of matériel; one that focused on causing so much loss of life that the enemy would be forced to surrender through sheer exhaustion. The war in became a siege, much like the medieval siege of a city, where gains were counted in yards and men lived in make-shift fortifications along a narrow front.

Image above: “The Battle of Pilckem Ridge. Three Irish Guards wearing German body-armour, examining a captured German machine-gun, at Pilckem, 31st July 1917.” [photograph], © IWM (Q 2636)
With trench warfare came new ways of fighting; both sides maintained that despite the static nature of the war, it was still to be fought aggressively, which meant raids, snipers and artillery barrages. With close hand to hand fighting during raids, particularly with knives, bayonets and even clubs, some of kind of extra protection may have seemed like a good idea.
Other than steel helmets, introduced in 1915 as a way to dimish the large numbers of head injuries occurring on the front, armour of any kind was not officially issued  for field use by the British High Command and it was left in the hands of private manufacturers to market many different types of personal protection.  These included armoured gloves and face protectors, and even chain mail enforced tunics, all available for purchase.
Most of what was available was probably not very useful, particularly against high speed and expanding bullets. Like many of the commercial products available for soldiers’ families to buy, armour was yet another gadget marketed as providing protection and comfort, but in reality only a gimmick.
Many sets were advertised as lightweight (which they frequently were not) or able to stop a bullet at a particular distance (which they largely failed to do). In the wartime landscape of mud and shell holes, weight and ease of movement became particularly important, as it was easy to fall into the mud and drown. While some soldiers may have bought trench armour (Robert Graves has an amusing story about being presented with it before he left for war in 1914), it appears not to have been used frequently.
By the Second World War, body armour had been completely discounted on all sides, and most soldiers went into battle with little more than a helmet to protect them. Interestingly, body armour has made a come-back in the post-World War II era and with the advent of light-weight, flexible materials like Kevlar, most soldiers serving in professional armies now wear some form of protective body gear.