Louis Dega was a prisoner in the French Guiana penitentiary as of 1932 (convicted on fraud for fifteen years) and companion of Henri Charrière, AKA "Papillon" for thirteen years. He had a younger brother named Joseph. Dega and Papillon had previously met before embarking to South America, and made a deal where Dega paid Papillon for protection. The two became best friends during their sentence. Wikipedia
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