Unlocking the World is the captivating history of the great port cities which emerged as the bridgeheads of this new steam-driven economy, reshaping not just the trade and industry of the regions around them but their culture and politics as well. They were the agents of what we now call 'globalization', but their impact and influence, and the reactions they provoked, were far from predictable. Nor were they immune to the great upheavals in world politics across the 'steam century'.