Ecu de 3 livres ou 60 sols Louis I

Louis I ruled Monaco under French protection following the 1641 Treaty of Péronne, which ended over a century of Spanish suzerainty over the principality. That political realignment explains the coinage entirely: Monaco's silver issues of this period mirror French monetary conventions closely, reflecting both economic dependency and diplomatic calculation. Louis reigned until 1701, making this a long-running type rather than a scarce transitional issue.

The 60-sol valuation places it squarely within the monetary reforms of mid-seventeenth-century France, where the livre tournois remained the accounting unit even as actual coin denominations shifted repeatedly under Colbert's fiscal reorganizations.