The Latin Monetary Union (hereafter LMU) was established in 1865 between France, Italy, Belgium and Switzerland. The agreement provided for the adoption of a common monetary base consisting of specie, and the adoption of the free circulation of gold and silver coins among them, whatever the issuing country. Despite its original goal, the minting of silver coins was subject to numerous restrictions (especially between 1874 and 1876) before being fully suspended by article nine of the convention of November 5 th 1878. The necessity for a lender of last resort quickly appeared in practice, even though the 1865 convention, and its numerous amendments, did not mention it in theory. The present article looks at how the idea of the lender of last resort was discussed in the context of the Latin Monetary Union. Specifically, it focuses on two opposing views on the LMU and its problems, as adopted by French economists at the time. The article concludes that the Banque de France played a crucial role in safeguarding the LMU. Referring to Bordo’s 1990 typology of lenders of last resort, we also add a fifth type, that of converter of last resort , to characterise the specific role played by the Banque de France.