The end of Europe's empires has so often been seen as a story of high politics and warfare. Tim Harper's new book shows how empires were fundamentally undermined from below. Using the new technology of cheap printing presses, global travel and the widespread use of French and English, young radicals from across Asia were able to communicate in ways simply not available before. These clandestine networks stretched to the heart of the imperial metropolises: to London, to Paris, to the Americas, but also increasingly to Moscow.