This beneficiary share No. 3.906 of the SA des Mines de Sentein et de Bagergue, issued in Paris in 1914, is a document unique in this collection for its cross-border Franco-Spanish character. The Sentein mines were located in the Ariège commune of Sentein, in the upper Salat valley, and had mainly extracted silver-bearing lead and zinc since the Middle Ages. The Bagergue mines, meanwhile, were located in Spanish Catalonia, in the upper Noguera Pallaresa valley, extracting similar minerals. The company thus managed mining operations in two different countries, linked by Pyrenean geology but separated by the national border. This cross-border organization required complex legal arrangements and illustrates the freedom of capital movement in Europe before the First World War. Beneficiary shares, representing a right to profits with no nominal value, were commonly used in mining companies. A document issued just before the outbreak of the First World War, which would upend the Pyrenean economy.