English mission organization, formed in 1966 by the merger of the Commonwealth Missionary Society and the London Missionary Society. The Commonwealth Missionary Society (originally the Colonial Missionary Society) was organized in 1836 to promote Congregationalism in the English-speaking colonies. The London Missionary Society was founded in 1795 as a nondenominational organization dedicated to spreading the Christian faith in the non-European world. Its primary support, however, was always from the Congregationalists. The society sent missionaries to the South Pacific islands and to Africa, China, India, and Southeast Asia. Its most famous representative was David Livingstone (Livingstone, David), the explorer-missionary who proved that Central Africa was accessible and who also exposed the slave trade.