The Missio sui Iuris: To Be or Not To Be a Particular Church (c. 371 §1): Historical Development of the Missio sui Iuris in Mission Territories (1896–2002) and the Praxis of the Congregation for the Evangelization of Peoples in Erecting Them

Towards the end of the 19^th century, the then-Sacred Congregation de Propaganda Fide began erecting the Missiones sui Iuris or independent missions as an alternative viable structure in areas where the mission diocese, apostolic vicariate or apostolic prefecture could not be initiated for various reasons. Although such a structure existed in limited circumstances from the time the Congregation was founded in 1622, it was after the First Vatican Council that the structure of an independent mission became more prevalent.

By the early 20^th century, the yearbooks of the Holy See, the Gerarchia Cattolica and the Annuario Pontificio, began listing independent missions initially to with the apostolic prefectures, and later as a separate category of particular church structure. An apparent anomaly is the historical reference published for decades in the Annuario Pontificio attributing this structure to the decree Excelsum of September 12, 1896. This decree from the Sacred Congregation de Propaganda Fide was addressed specifically to territories under the jurisdiction of the Oriental Churches in the Middle East, and it was never explicitly cited in any of the documentation of the general congregations of the 19^th and early 20^th centuries where independent missions were erected.

The Missio sui Iuris was omitted in the 1917 Code of Canon Law, but both Benedict XV and Pius XI recognized the structure as one of four structures in mission territories. While the independent missions were omitted in the 1983 Code of Canon Law, in the 1980’s and until 2002 the structure was again employed for special missionary circumstances. Today there are eight independent missions listed in the Annuario Pontificio, and these structures continue to follow the criteria originally established for them: an ecclesial structure erected from a previous territory, with explicit boundaries, under the care of a religious community or other diocese, responding to a missionary exigency and headed by a superior nominated by the Holy See, under the aegis of the Congregation for the Evangelization of Peoples.