In business history, it has become a well-accepted fact that engineers have lost territory to business school candidates in the most recent phases of modern capitalism. This article puts up for debate whether business historians studying Northern Europe have perhaps been too willing to accept this diminishing role of the engineer in the understanding of national business systems? What we find, looking at three successful Danish businesses since the late nineteenth century, is a persistent importance of what we term the engineer capitalist. Thus, across three different periods we find that engineer entrepreneurs, who were on the forefront of technical knowledge and who came up with innovative ideas for products with a strong commercial potential in international markets, stand out as drivers of innovation and internationalisation. This leads to a preliminary theory of engineer capitalism and to a contribution to the ongoing reinterpretation of Danish business history.