Question

Why was the Battle of the Somme important during World War I?
Great Britain uced unrestricted submarine warfare for the first time
It showed how trench warfare could help quickly win the war
Germany's Schlieffen Plan was successful
One million soldiers died without any clear winner

Answer 1

One million soldiers died without any clear winner.

Each side suffered about half a million casualties, and Germany advanced 4 miles and the British gained 5 miles.

So, but suffered mass casualties and no one made any significant gain.