The battle at Somme in World War I was the most deadly in history

Daniel Hannan:

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"Somme," wrote a Prussian veteran afterwards. "The whole history of the world cannot contain a more ghastly word." The first day remains, by some measure, the worst in the history of the British Army: An almost unbelievable 19,200 men were killed.

In the five months that followed, 400,000 British and Allied troops, and a similar number of Germans, lost their lives, without any noticeable gain or loss of territory. It was that territory, pock-marked by artillery, filled with toxic gas, devoid of any living thing except enemy patrols, that later inspired Tolkien:

Here nothing lived, not even the leprous growths that feed on rottenness. The gasping pools were choked with ash and crawling muds, sickly white and grey, as if the mountains had vomited the filth of their entrails on the lands about.

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Almost every British family was touched, as mine was, by the tragedy. My old school lost 749 students, a number which I still struggle to take in. Like so many schools, many of its present buildings were erected as monuments to the slain: We were educated, I now realize, in a semi-mausoleum.
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It was a battle that helps explain the reluctance of British politicians to challenge Hitler until it was almost too late at the beginning of World War II.

Much of the grisly results is explained by the machinery of warfare that made previous tactics fail completely.  Heavy machine guns and artillery ground everything down that tried to cross the no mans land between the trenches.  This trend started in the American Civil War, and did not end unto close to the end of World War I when planes and tanks were introduced to the battlefield in a way replaced the horse cavalry that was no longer effective.

The battle took place in France near the place where Henry V won the Battle of Agincourt on Saint Crispin’s Day, October 25th 1415 during the 100 Years War.