Largest empire by population

At the outbreak of World War I in 1914, the population of the British Empire had stood at 88 million. By 1922, however, following the acquisition of additional territories in the wake of that war, this figure had grown to some 458 million. The population eventually peaked in 1938, on the eve of World War II, by which time the British Empire accounted for an incredible 531 million people, making it the largest empire in history by population. Today, it is estimated that the British Commonwealth includes as many as 2 billion people spread across its 54 member states.