According to Charles Tilly’s famous formula, “war made the state, and the state made war.” War and the necessity to equip and pay the salaries of vast armies and navies drove early modern states to develop new methods for raising revenues through taxation and public borrowing. The impact of frequent conflicts during the early modern period on trade and the world of private finance is a more complex legacy and is less well understood. In my presentation, I shine a spotlight on marine insurance, a financial instrument that is often overlooked by economic historians. I use notarial registers from the port of Marseille to study how the structures and prices of insurance coverage were transformed during wartime. I show how traders in Marseille refashioned marine insurance policies as speculative instruments.