Empires of Sand is a 1999 novel by American writer David W. Ball.
It tells the story of two cousins who grow up together in Paris but are separated during the Franco-Prussian War.
The second half of the novel concerns their adventures in French Algeria, one cousin living with a Tuareg tribe, the other a French lieutenant on the real-life Flatters Expedition, an ill-fated mission initiated by the French government in 1881 to survey a railway route through the Hoggar region of the Sahara desert.
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