Due to newly peaceful conditions, trade thrived between 1860 and 1880. Taking advantage of this were Christian missionaries. The Lutherans and the London Missionary Society both became established in the country by 1856. By 1880 every major village had a resident missionary, and their influence slowly became felt. Khama III (reigned 1875–1923) was the first of the Tswana chiefs to make Christianity a state religion and changed a great deal of Tswana customary law as a result. Christianity became the de facto official religion in all the chiefdoms by World War I.