We construct a new, comprehensive instrument-level database of sovereign debt for 18 advanced and emerging countries during 1913–46, an eventful period characterized by notoriously high debt levels. This database is thus the first to provide public debt time series with such a high degree of comparability across countries and time. Documentation of qualitative instrument characteristics offers unique insights about the debt management policies that were implemented and the broader policies they helped finance. We document how interwar governments rolled over debts that were largely unsustainable and how the external public debt network contributed to the collapse of the international financial system in the early 1930s.