At the height of its greatness in the late 19th and early 20th century, it included 25% of the world's population and area. What was it?
The answer that the teacher or professor is most likely seeking is the British Empire. At its peak during the late-19th and early-20th centuries, the British Empire -- one of several European-dominated empires upon which, the saying went, the sun never set -- occupied a quarter of the world's land mass and population, including the vast South Asian territory of modern-day India and Pakistan. British colonial holdings extended from the tiny Falkland Islands in the South Atlantic (territory it still holds but that is contested by Argentina) to Australia and New Zealand on the other side of the Earth. Interestingly, the period in question -- the late-19th to the early-20th centuries -- excludes, for obvious reasons, Britain's once considerable colonial holdings in the portion of North America that became the United States of America. Those holdings were relinquished as a consequence of the victory of the 13 colonies against the British crown during the late 18th century. Great Britain continued to hold, however, the expansive territory of Canada, which, together with the Indian subcontinent, represented a major percentage of the world's landmass.