This paper presents a model of serendipitous entrepreneurship that integrates the perspectives of life-course theory and capital theory to derive testable predictions for how the accumulation of human, social and cultural capital interacts with important life-course events, shaping the likelihood of individuals’ entry to exit from entrepreneurship. The predictions are tested on a random population of individuals whose life-courses are reconstructed using archival data. The results provide strong support for our model and suggest a more dynamic view of the entrepreneurial process than is offered by capital theory. Our model challenges the view of entrepreneurship as an occupational choice driven by the rational decisions of individuals to exploit their human capital.