On 1 November 1947, Joseph du Bouchet arrived in Fort-Lamy. He had just been appointed apostolic prefect of Chad. To welcome him, his colleague Charles Margot gathered the entire colonial elite of the city. Military honours followed du Bouchet's arrival. A solemn mass was celebrated on the site of the future Cathedral of Notre Dame. By noon, the European Fraternity of Fort-Lamy had received du Bouchet. The next day, on the Commemoration of All the Faithful Departed, he presided at another eucharistic celebration in the cemetery where Commandant François Lamy, explorer and conqueror of Chad, was buried.

The French military establishment in Chad stood by du Bouchet's side. Madame Leclerc, wife of the famous general who led French Sub-Saharan African troops in the Second World War, sat in the front row. She was the main benefactress for the construction of the new cathedral. A few months later, on 15 February 1948, du Bouchet wrote to the national chaplain of the veterans in Paris, asking for their support for the Chad Mission. Since Chad was an important French military base, some veterans in Paris had been there and were willing to throw their support behind the mission.

During du Bouchet's welcoming ceremony on the site of the cathedral of Fort-Lamy, the new head of the mission noticed the presence of some ‘brave Blacks’. Amid traditional songs and dancing, these Africans brought many gifts. With the help of three interpreters, some of them asked for blessings to be given to their rosaries and themselves. Among these Africans, the head of the Cameroonian immigrant ‘colony’ in Fort-Lamy offered a welcoming address to du Bouchet. Other Cameroonians quickly put themselves forward to become Jesuits.

J. du Bouchet's arrival officially ended the exploratory period of the Chad Mission (1931–46). To mark that rupture, du Bouchet denied the return of the founder of the mission, Frédéric de Bélinay, to Chad. His predecessor, he believed, would be more useful to the mission if he remained in Paris. Moreover, the official recognition of the mission by the Vatican, and the subsequent ecclesiastical organisation of the mission that followed, seemed to initiate a brighter horizon for the Africanisation of its personnel and leadership which the Vatican was pushing for. In practice, having a sitting bishop in Chad was a positive step towards recruiting and training a local clergy and lay personnel for the mission.