Abstract: British emigrants tend to be lost in their vast numbers and in their historiographical anonymity. They feature very marginally in most interpretations of British expansion in the age of imperialism. There was a remarkable surge in emigration in the 1820s which presaged the Age of Emigration in the Victorian era. This was also a prototype of modern international migration. The origins of this momentous increase in emigration are unclear but recent emphasis gives priority to the influence of the new forms of propaganda and ‘puffery’. In this article it is contended that more consideration should be accorded to bedrock changes in British demography and agrarian life in the propulsion of this mass emigration, which eventually involved about 19 million people from the British Isles in the long nineteenth century.