World War I is not the bloodiest war in the history of war, but rapid advances in technology as well as the failure of military leaders to adjust their tactics resulted in possibly the bloodiest day in British military history when the nation lost almost 20,000 troops at the Battle of the Somme on July 1, 1916.
The roots of the bloodshed of July 1 date back before the war even started as the Gatling Gun gave way to true machine guns, originally known as "gunpowder engines," and advances in mortars, artillery, and even the standard rifle made soldiers of all types much more lethal.
But, importantly, many of these breakthroughs favored static defenses. Soldiers could march forward with machine guns, but they would struggle to quickly emplace them and get them into operation. Defenders, meanwhile, could build fortifications around their machine guns and mow down enemy forces with near impunity.
After the war started in 1914, Germany managed to quickly move into France before getting bogged down in a line that eventually stretched across Europe. A German attack at Verdun in early 1916 became a black hole for French troops. The attack was designed to bleed France dry and force it out of the war.
The Germans expected Britain to launch its own attack against German lines to relieve the pressure from France. And Britain did have a plan for an attack, but it would prove to be a failure.
A joint British-Franco assault was scheduled for the summer. The main thrust was to come along a narrow stretch of the River Somme and the first day would see approximately 100,000 British troops rushing German lines in what was hoped to be a quick advance.
The date was eventually set for July 1, 1916, and the British initiated a massive artillery bombardment for a week before the assault. But the Germans were able to move most of their troops into fortifications in the trenches, and relatively few troops were lost in the week before the British attacked.
When the artillery suddenly stopped on the morning of July 1, German machine gunners moved back to their positions and looked up to see thousands of British troops marching towards them.
The machine gunners opened up, artillery spotters started calling for fires, hell rained down on British troops.
The day wore on, and British troops kept marching across. Entire units took losses of 90 percent, basically wiping them out. British forces took 60 percent casualties wounded, missing, and killed. Approximately 19,240 of which were fatalities. They had taken three square miles territory.
Since France suffered 190,000 casualties during the fight in the Somme, even that is a dubious success.
But the battle wasn't over. While small changes in tactics and the later introduction of the tank reduced the number of casualties that Britain took, the battle would wage on for five months and the combatants eventually inflicted over 1,000,000 casualties on one another.
While Britain failed to take most of its planned objectives despite throwing hundreds of thousands of men into the grinder, one part was successful. German forces were forced to move some artillery and troops from the attack on Verdun to the Somme, relieving pressure on the French defenders.