What was the deadliest battle in history?

The Battle of Stalingrad was a brutal military campaign between Russian forces and those of Nazi Germany and the Axis powers during World War II. The battle is infamous as one of the largest, longest and bloodiest engagements in modern warfare: From August 1942 through February 1943, more than two million troops fought in close quarters – and nearly two million people were killed or injured in the fighting, including tens of thousands of Russian civilians. The giant campaign was really a showdown between Hitler and Stalin over the city that bore the name of the Soviet dictator, which ultimately turned the tide of World War II in favor of the Allied forces, and helped bring about a change of fortunes that would eventually destroy Nazi Germany and doom Hitler.