[2] In 1857 and 1858, Duveyrier spent some months in London, where he met Heinrich Barth, then preparing an account of his travels in the western Sudan.

After his release he made several further journeys in the Sahara, adding considerably to the knowledge of the regions immediately south of the Atlas Mountains, from the eastern confines of Morocco to Tunisia.

Duveyrier devoted special attention to the customs and speech of the Tuareg people, with whom he lived for months at a time, and to the organization of the Senussi.

[1] Duveyrier was adversely affected by the tragedy that befell the Flatters Expedition of 1880–81 which put an end to the proposed Trans Sahara railway and military expansion in the region.

Duveyrier's only error was in having described the Tuareg as veiled, turbaned medieval paladins; but the explorer was already shaken by the premature death of his fiancée, and embittered by the controversy, he committed suicide in 1892.