In 1865, France, Belgium, Italy and Switzerland signed a monetary convention(later known as the Latin Union), which provided for the intercirculationof specie between member states. Conventional analyses of the treaty (suchas that by Willis) have portrayed this arrangement as a by-product of Frenchpower politics. This article seeks to reinterpret the economic nature of theLatin Union, focusing on the interrelations between trade, finance and money.I argue that the Latin Union did not foster trade integration and that, asa matter of fact, such was not its objective, according to archival evidence.Instead, I suggest that the Latin Union was the result of the growth of Franceas a major supplier of capital. The need to provide French investors withexchange-rate guarantees led borrowing countries to tie their respective monetarysystems to that of France. This, in turn, created opportunities for internationalmonetary action and the French franc became the ‘natural’ focalpoint of projects of monetary unification. This evolution, however, had structurallimits which help to explain the downfall of the projects for expansion ofthe Latin Union.