William Stanger was best known as a surveyor-general in the Cape Colony and the Colony of Natal, but was also a geologist, botanist and medical doctor. He was the son of Willam Stanger and Mary Dent. He studied medicine and natural science at Edinburgh University, and after returning from a trip to Australia and New Zealand, ran a practice in London for some time.

The Niger expedition of 1841 was mounted by British missionary and activist groups in 1841–1842, using three British iron steam vessels to travel to Lokoja, at the confluence of the Niger River and Benue River, in what is now Nigeria. The British government backed the effort to make treaties with the native peoples, introduce Christianity and promote increased trade. The crews of the boats suffered a high mortality from disease.