1951.06.14: Established as Apostolic Prefecture of Isangi / Isangien(sis) (Latin) (from Apostolic Vicariate of Stanley-ville, Apostolic Vicariate of Basankusu and Apostolic Vicariate of Lisala)
1962.07.02: Promoted as Diocese of Isangi / Isangien(sis) (Latin)