When Louis XIV revoked the Edict of Nantes in 1685, perhaps 200,000 Huguenots — French Reformed Protestants — fled to England, Prussia, the Dutch Republic, Switzerland, the Cape, and the American colonies. They concentrated in textiles, watchmaking, banking, and military officer corps. The departures hollowed out specific French industries (most famously the silk trade of Lyon and Tours) and built up corresponding sectors elsewhere — Spitalfields silk in London, Berlin's early manufacture, Geneva watchmaking, the Bank of England.
The community brought consistory governance — a Reformed elder-council tradition — which it reproduced in each host country, providing not only worship but mutual aid, vocational matching, and credit. Within a century most Huguenot descendants assimilated into host populations, but the trades they brought and the institutions they founded persisted longer than the distinct community itself.
The Huguenot case is the clearest historical demonstration of a particular survival-intelligence conclusion: persecution that targets a productive minority is not just morally wrong; it is strategically self-defeating for the persecuting state. France's loss was Britain's, Prussia's, and the Netherlands' gain.