World War I had been raging for nearly two years, and the western front had devolved into a stalemate.  To break the impasse, the British hatched a battle plan they thought would break the German lines and bring them victory.

They chose a narrow front along the river Somme to make the attack.  What transpired next was maddening incompetence bordering on criminal negligence by the British army.

Every officer and noncom in the army knew that frontal assaults on prepared positions resulted in slaughter.  But the British general in command, Douglas Haig, believed that the key to victory was in a massive artillery bombardment that lasted a full week.  But the shells had little effect on the German defenders, who, once the fire slackened, came out of their bunkers to man thousands of machine guns.  The results were predictable:

Journalist and cartoonist Joe Sacco, who illustrated a massive panorama of the first day of the battle, spoke to NPR in 2013. Here's what we wrote then:

"The battle began on 7:30 a.m., July 1, 1916, on the river Somme in France. There had already been a series of bombardments; British generals unloaded a week's worth of artillery, thinking it would decimate the Germans and allow British troops to move in easily.

"But while the bombardment was so loud that it could be heard in London, it hadn't been very effective; many of the shells were duds, and others just hadn't done the job. Then the barrage lifted, and the troops started to move.

" 'When all that noise quieted down, the Germans realized, OK, the shelling has stopped; let's get out of our dugouts and man our machine gun posts,' Sacco says. 'The British were marching towards them in a line, and the Germans just started firing on these troops.' "

It was a test of new battle tactics, and it was a devastating failure. More than 19,000 British soldiers were killed in the first day alone — the deadliest day in the history of the British military. Nearly 40,000 more were injured.

The "tactics" were essentially the same as those that had been used for two years.  An entire regiment from Newfoundland was butchered in the first day.  So-called "pals regiments" made up of chums from neighborhoods and schools around Great Britain were slaughtered, leaving many communities devastated.

If there is a battle that defined the useless slaughter of World War I, the 117-day bloodletting by the British army at the Somme river to advance a measly ten miles is it.