During the early-modern period, the capacity of European states to raise finances, wage wars, make their own and far away populations subjects, and exert bureaucratic power over a variety of areas of social life increased dramatically. Nevertheless, these changes were far less absolute and definitive than the literature on the rise of the “modern state” once held. While war expanded the boundaries of the emerging fiscal military states of the seventeenth and eighteenth centuries, rulers remained highly dependent on negotiations with competing elite groups and private networks of contractors and financial intermediaries. Attempts to increase control over subjects often resulted in popular resistance, limiting and influencing the direction of the development of state institutions. Marjolein ’t Hart has been and remains in the front lines of developing this new approach challenging a unilineal view of the transformation of European states. Starting from her innovative work on taxation, state finance, and the economics of warfare in the Low Countries during and after the “Dutch Wars of Independence”, she has contributed significantly to the literature on European state formation and extra-European expansion in a comparative perspective. This introduction offers an overview of the scholarly career of ’t Hart, and places the contributions that follow in the context of her work.