Cartographic extent vs effective control: auditing the size of empires

Why "the largest empire in history" is a statement about maps, not about government. The size series behind every popular ranking are atlas reconstructions; this object audits the famous figures - Britain's 35.5 million km2, Spain's claimed 25 million, the rival "effective" estimates - and publishes the territorial audit's verdicts, including its rejection of the "Spain integrated, Britain segregated" dichotomy as a scoring device.