This article analyses the activities of several European missionaries who worked in Lesotho, Zambia, Mozambique and the Transvaal in the 19th century through the missions of Paris (Société des Missions évangéliques de Paris, founded in 1822) and Lausanne (Mission romande, former Mission vaudoise, 1874). The focus is on how these missionaries developed their personal interests outside their mandate. Know-ledge and money were at stake. While some activities were made public, others were treated with the greatest discretion. This affected and shaped the way in which the missionary memory was constructed. The sources used for this study are listed in a database created by the authors themselves, with a multidisciplinary team in Italy: missioniprotestanti-africaaustrale.org (online since 2022, interactive from 2024).