Where has sustainability come from and how could it become such a popular idea? This special issue analyses the intersection between twentieth-century attempts to attune environmental, social and economic concerns in the Low Countries and the rise of ‘sustainable development’ from the 1980s onwards. The introduction to this issue first relates the articles to the international historiography on sustainability and elaborates their shared approach. Second, the varieties of sustainability practiced in Belgium, the Netherlands and Congo – as analysed in the contributions on forestry, breweries, pisciculture, water management, agriculture, and the alternative food movement – are presented. Based on their results, the period from the 1940s until the 1990s can be characterised as an ‘age of interdependence’ during which a distinct notion of sustainability emerged. Sustainability was interpreted in the light of global interconnections. Transnational governing coalitions, aided by experts and the ideal of planning, were established to achieve a balance between environmental, social and economic interests. The environment became an important object of post-war public debate and policy because of its connections to society and the economy. Building on these histories of sustainability, the introduction finally explores how historians enhance our understanding of the Anthropocene. Waar komt duurzaamheid vandaan en hoe kon het idee zo populair worden? Dit themanummer analyseert het snijvlak van twintigste-eeuwse pogingen om ecologische, sociale en economische belangen in de Lage Landen met elkaar in evenwicht te brengen en de opkomst van ‘duurzame ontwikkeling’ vanaf de jaren 1980. De inleiding positioneert de bijdragen in de internationale geschiedschrijving van duurzaamheid en licht hun gemeenschappelijke werkwijze toe. Vervolgens peilt de inleiding de invullingen van duurzaamheid in België, Nederland en Congo, zoals die in de bijdragen over bosbouw, bierbrouwerijen, viskweek, waterbeheer, landbouw en de alternatieve ...