British naval surgeon and explorer. After serving in the British navy during the Napoleonic wars, Walter Oudney returned home to Edinburgh, graduated as an MD and set up in private practice. An accomplished botanist, he became a member of the Wernerian Society and studied chemistry and natural history in hope of becoming a lecturer in botany at Edinburgh University.
When two British attempts to discover the source of the Niger River from west Africa failed, it was decided to make an approach from Tripoli, where cordial relations with the Turkish pasha, Yusuf Karamanh had been established. On the recommendation of James Robinson Scott, a former botany lecturer at Edinburgh University, Oudney, who had expressed a keenness to go to Africa, was appointed as leader of the expedition in 1821. At Oudney's request, a fellow naval officer from Edinburgh, Hugh Clapperton, became his assistant.
After Oudney arrived in Tripoli in 1821, he found that his position as leader had been usurped by a British Army major, Dixon Denham. Having originally volunteered to lead a scientific expedition, he now found he had been appointed to become vice-consul of Bornu (later Nigeria) with the task of exerting diplomatic pressure to increase British standing there. Travelling south, the three explorers arrived in Murzuq in Fezzan on 7 April 1822 where they were delayed for months while waiting for a military escort to be formed. Finally in November the expedition caravan set off across the Sahara Desert, an exhausting trek that brought Oudney and his companions to Lake Chad, the first Europeans ever to reach it. While Denham set out to circumnavigate the lake to determine whether it was the source of the Niger, Oudney and Clapperton journeyed west to discover the Chari River, flowing into Lake Chad from the south, and then headed for the large and cosmopolitan market centre of Kano. On the journey, Oudney caught pneumonia and died on 12 January 1824.
Although the question of the Niger's source remained unresolved, some of Oudney's mineralogical notes and geographical information were later included the 1826 publication of Narrative of Travels and Discoveries in Northern and Central Africa by Denham, and some hundred of his natural history specimens were brought back to England.