If you’re looking for stupid, pointless wastes of human life in the First World War, you really are spoilt for choice, but, even among such inauspicious company, the Gallipoli campaign manages to stand out as particularly stupid and particularly pointless.
To sum up: The Ottoman Empire sort-of-accidentally entered the war on the side of the Germans, the allies were at a complete stalemate and Winston Churchill suggested trying something a bit different. In theory this meant smashing through a passage to Russian Black Sea ports to the Mediterranean, in practice it meant sending shiploads of conscripts to disembark on exposed beaches and get shelled by Turkish soldiers.
One memorable account has a party of British officers arranging a conference with local Ottoman officers, whose first question is “Why are you here and why are you letting us shoot your men?”
Needless to say, anything on this subject is unlikely to relent in its grimness.