• The concept of “air superiority” was unheard of before 1914, but winning the war in the skies became a tactical necessity by the end of the Great War.

• The main military role of aircraft in World War I was reconnaissance (military observation of a region to locate an enemy or ascertain strategic features.)

• Due to trench warfare's static nature, aircraft were the only means of gathering information beyond enemy trenches, so they were essential for tracking the movement of enemy troops and mapping terrain.

• Aerial observation and artillery spotting became common uses for airplanes; commanders incorporated information acquired by pilots and observers into battle plans.

• Aircraft were also used to support ground troops. During ground attacks, explosives, such as grenades and bombs, were dropped from a low altitude to ensure accuracy, and machine guns were fired at targets on the ground.

• Aircraft could only carry a small bomb load during this time, but these methods were used during WWI, as was the practice of throwing grenades and even grappling hooks at the enemy. Fighter pilots became known as aces when they reached five or more aerial casualties and victories. By the end of the war, over 1,800 soldiers became known as aces.

• Long, narrow trenches dug into the ground at the front, usually by the soldiers who would occupy them for weeks at a time, were designed to protect troops from machine-gun fire and artillery attacks from the air. Both sides mounted attacks from the trenches, with blades fixed to their rifles, by climbing over the top edge into what was known as “no man’s land,” the area between opposing forces, usually in a single, straight line and under a barrage (bombardment) of gunfire.

• As the “Great War” also saw the wide use of chemical warfare and poison gas, the trenches were thought to offer some degree of protection against exposure.  Trenches may have afforded some protection by allowing soldiers more time to take other defensive steps, such as putting on gas masks. 

• Trenches in WWI were constructed with sandbags, wooden planks, woven sticks, tangled barbed wire or even mud.  With soldiers fighting nearby in the trenches, usually in unsanitary conditions, infectious diseases such as dysentery, cholera, and typhoid fever were common and spread rapidly. Constant exposure to wetness caused trench foot, a painful condition in which dead tissue spread across one or both feet, sometimes requiring amputation. As they were often effectively trapped in the trenches for long periods, under nearly constant bombardment, many soldiers suffered from “shell shock,” the debilitating mental illness known today as post-traumatic stress disorder (PTSD).

• It’s likely all of these factors, which stemmed from the widespread use of trench warfare, made World War I the deadliest conflict in global history to that point. It’s believed that as many as one in 10 of all fighting forces in the conflict were killed.

• By the end of 1914, after just five months of fighting, the number of dead and wounded exceeded four million men.

• The first large-scale use of lethal poison gas on the battlefield was by the Germans on 22 April 1915 during the Second Battle of Ypres. This was the first major gas attack by the Germans, and it devastated the Allied line.

• Immediately after the German gas attack at Ypres, France and Britain began developing their own chemical weapons and gas masks

• The development, production, and deployment of war gases such as chlorine, phosgene, and mustard created a new and complex public health threat that endangered not only soldiers and civilians on the battlefield but also chemical workers involved in the large-scale manufacturing processes.

• Mustard gas blistered the skin, eyes, and lungs and killed thousands. Military strategists defended the use of poison gas by saying it reduced the enemy’s ability to respond and thus saved lives in offensives. In reality, defenses against poison gas usually kept pace with offensive developments, and both sides employed sophisticated gas masks and protective clothing that essentially invalidated the strategic importance of chemical weapons..

• In all, more than 100,000 tons of chemical weapons agents were used in World War I, some 500,000 troops were injured, and almost 30,000 died, including 2,000 Americans.

• Barbed wire and machine guns stopped many Allied attacks, with heavy casualties in 1915 and early 1916.

• The British developed tanks as one way to cross “No Man’s Land” and break through the enemy trench system.  The tanks became the solution to the stalemate.

• They were first used on the battlefield in Somme in September 1916, but they were mechanically unreliable and too few to secure a victory. They were also hot, noisy, and hard to move around, and they suffered mechanical malfunctions on the battlefield. However, people realized the tank’s potential.

• Further design improvements were made, and the Battle of Cambrai in November 1917 proved much more successful. The tanks captured 8,000 enemy troops and 100 guns, and they rapidly became an important military weapon.

• World War I popularized the use of the machine gun, which could bring down row after row of soldiers from a distance on the battlefield. This weapon, along with barbed wire and mines, moved to open land both difficult and dangerous. Thus, trench warfare was born.

• Perhaps more than any other weapon, the machine gun drove soldiers from the battlefield into the trenches. Overcoming the stalemate created by the dominance of firepower would challenge armies for the rest of the war.

• The average machine gun needed two or three men to fire it, but most guns were operated by teams of four. By 1918, however, one-man portable machine guns were put to some use, although maintaining sufficient ammunition supplies remained a difficulty.

• As the war developed, machine guns were adapted for use on tanks on broken ground and mounted on aircraft. In response to their increasing success, it was inevitable that machine guns should similarly be mounted on vehicles and added to warships, a useful addition to naval armaments.

• Thought of as the war to end the war, over 9 million soldiers were killed in the conflict, and 21 million were injured. The war largely helped these casualties by being the first to feature the widespread use of machine guns.

• Submarines played a significant military role for the first time during the First World War. Both the British and German navies used their submarines against enemy warships from the outset. The German government used extensive submarines, initially against warships and then, as the war progressed, most heavily against merchant shipping.

• Germany led the way in submarine technology and production. Germany’s large, long-range submarines were known as U-boats. These vessels could reach maximum depths of 165 feet, achieve speeds of 16 knots at the surface and eight knots underwater, and have a range of up to 25,000 miles. They were armed with deck-mounted guns and up to 16 self-propelled torpedoes.

• The U-boats operated far out in the oceans as Germany tried to cut off Allied supply lines and destroy their opponents’ ability to wage war.   Since torpedoes of this period could be unreliable, surface attacks were quite common; this tactic also allowed U-boat crews to seize supplies and valuables from merchant ships before they sunk. Furthermore, some U-boats were equipped to transport and deploy naval mines.

• Initially, when U-boats encountered merchant ships, they surfaced before they attacked and allowed those on board time to escape. However, in February 1915, the Germans changed their tactics. U-boats began to fire on ships without warning, including neutral and passenger vessels.

• The damage inflicted by U-boats during World War I was powerful. Their ability to submerge and to surprise enemies led to massive casualties.  Germany and Austria-Hungary sank almost 5,000 merchant ships during World War I, killing approximately 15,000 Allied sailors.

• Using portable flamethrowers in combat was an innovation of the First World War. The German army led in developing this form of warfare and remained the foremost practitioner throughout the war.

• The man-portable flamethrower consists of two elements—the backpack and the gun. The backpack element usually consists of two or three cylinders; one holds compressed, inert propellant gas (usually nitrogen), and the others hold flammable liquid, typically petrochemical.

• The gun consists of a small reservoir, a spring-loaded valve, and an ignition system; depressing a trigger opens the valve, allowing pressurized flammable liquid to flow and pass over the igniter and out of the gun nozzle.

• Flamethrowers were primarily used against battlefield fortifications, bunkers, and other protected emplacements. They project a stream of flammable liquid rather than flame, which allows bouncing the stream off walls and ceilings to project the fire into unseen spaces, such as inside bunkers or pillboxes.

• The first disadvantage was the weapon's weight and length, which impaired the soldier's mobility. The weapon is also limited to only a few seconds of burn time since it uses fuel very quickly, requiring the operator to be precise and conservative.

• The weapon was very visible on the battlefield, immediately identifying operators as prominent targets, especially for snipers and designated marksmen.

From the beginning of military warfare, communication has often held the keys to victory. Communicating with your allies while knowing where your enemies are is one of the most crucial parts of war.

However, this new technology was not always the best way to communicate. Weather, terrain and the enemy could break the electric lines connecting the front line to their commanders.

Telegraph and Morse code - The electric telegraph sends an electric current to a receiving station. When the sender presses the telegraph key, he interrupts the current, creating an audible pulse that is heard at the receiving station. Morse code is a system of sending messages by a series of on-off tones, lights, or clicks. Each letter is represented by a unique series of short dots (dits) and longer dashes (dahs).

Signal lamps—The U.S. military used the electric signal lamp, a form of communication that is a visual signal often restricted by one’s line of sight.

Telephone—The telephone was developed by improving the electric telegraph. A telephone converts sound (from our voice) into electronic signals suitable for transmission via cables or other media over long distances. It replays those signals simultaneously so we can hear them. Alexander Graham Bell received the first patent for the telephone in 1876. During WWI, on the Western Front, telephones were used to communicate between the front-line Marines and Soldiers and their commanders.

 Wireless Telegraph (Radio)—Radio debuted years before World War I. Ships often used it to transmit messages via Morse code. Radio's biggest improvements over message systems like Morse code were the speed and accuracy of voice communication.