German military physician, colonizer and explorer of the Sahara who helped Germany obtain protectorates in western equatorial Africa.
After spending several years as a military surgeon, Nachtigal went to Tunisia as physician to the bey (ruler) and took part in several expeditions to the interior. In 1869 the king of Prussia, William I, sent him on a mission to the kingdom of Bornu, now in northern Nigeria. He travelled by way of central Sahara regions then unknown to Europeans, including the Tibesti and Borkou regions, which today lie within northern Chad. From Bornu he crossed the sultanate of Baguirmi, also in Chad, and, continuing by way of the Kordofan province of the Sudan, reached Cairo in November 1875. Sah?râ und Sûdân (1879–81) gives an account of his expedition. While serving as German consul at Tunis (1882–84), he was sent by Bismarck to western Africa ostensibly to make trade agreements but secretly to help secure German protectorates over regions now in Togo and Cameroon.
Gustav Nachtigal is regarded as the other great German explorer of Africa, in company with Heinrich Barth. Like Barth, Nachtigal was primarily interested in ethnography, and additionally in tropical medicine. His works stand out because of their wealth of details and above all because of his unbiased views of Africans. In contrast to most contemporary explorers, Nachtigal did not hold to the alleged inferiority of Africans; his convictions are clearly reflected in his descriptions and choice of words.
He died 19 April 1885, at sea, off Cape Palmas, Liberia.

Link to Wikipedia biography