The Great War was the first war in which entire industrialized societies were mobilized for the sole purpose of waging total war. For four years, million-man armies faced each other across the battlefields of Europe with further fighting raging in the Middle East and Africa. When the guns finally fell silent, many of Europe's empires would be no more.

There are currently 33 statistical series on World War I.

World War II remains the most devastating conflict in human history and one which saw the entire military, industrial, and scientific resources of the world's major powers dedicated solely for the purpose of ultimate victory across Europe, North Africa, and the Pacific. It was also a war that was fought as ferociously on air and sea as it was on land.

There are currently 109 statistical series on World War II.

The Cold War was a half-century period of intense military and geopolitical rivalry between the world's two superpowers, the US and USSR, amid the ever-present threat of a nuclear armaggedon. The fall of the Berlin Wall in 1989 did little to make the world safer, as evidenced by the numerous regional conflicts that have broken out since.

There are currently 30 statistical series on the postwar period.