French projects for colonial penetration in southern Algeria between 1830 and 1880

French colonial policy in Algeria aimed to extend its control over the entire Algerian territory. To achieve its objectives, it adopted a variety of methods, including political, economic, and military approaches, as well as a missionary religious strategy. Through the latter, France attempted to Christianize Algerians, but it failed despite its covert efforts. This strategy was realized through the work of missionaries and explorers, who paved the way for occupation. This research article seeks to reveal the colonial plans that enabled France to penetrate and occupy southern Algeria. It examines a well-defined strategy, including exploration missions, projects implemented to expand its influence, proselytism campaigns, and the policy of expansion in southern Algeria.