This very rare Medal recalls that period of history when great African explorations were undertaken, many involving the Royal Geographical Society.
In 1878, Alexander Keith Johnston (1844-79) was appointed to lead a Royal Geographical Society Expedition to find the head of Lake Nyassa but he died the following year, some 120 miles from Dar es Salaam. Joseph Thomson (1858-1904), the geologist and naturalist of the Expedition, took his place as leader. Although not completing the Expedition's objective, Thomson did reach Lake Tanganyika in November 1879 and was thus able to confirm Henry Stanley's theory as to the Lukuga outlet of the lake. For his efforts as leader, Joseph Thomson received the R.G.S. Gold Founders Medal in 1885.
The R.G.S. East African Expedition Medal 1878-80 would have been presented to members of the Expedition, the above example showing every sign of having been worn.