This article derives from one in Danish published by the National Archives of the Kingdom of Denmark in its Commercial History Yearbook (Hansen 2022; link). The article provides an account of the origins of Danish rent control and other housing regulations during World War II. Danish politicians reintroduced rent control in the autumn of 1939, but at non-binding levels. Due to inflation, rent control became binding in late 1942, and vacancies disappear. These problems led to compounding interventions. Rent control and adjunct interventions never brought any discernible benefits and were particularly harmful to landlords. Arguably, rent control increased inequality by favouring the wealthier segments of society. Politicians completely overlooked the secondary effects of rent control. I suggest that freedom plus governmental efforts focused on supporting vulnerable groups would have worked better.