It was erected as an apostolic vicariate on 10 Aug. 1920, with territory taken from the mission of Canton (q.v.), and was named the apostolic vicariate of Western Kwangtung and Hainan; this was changed to its present name on 3 Dec. 1924; on 15 Apr. 1924, the island of Hainan (q.v.) was erected into a separate mission. On 11 Apr. 1946, with the establishment of the episcopal hierarchy in China, it was raised to the status of a diocese, a suffragan of Canton. It has been entrusted since its beginning to the Paris Foreign Missions Society.
It covers an area of 22,000 sq. km. As of 30 June 1930, out of a total population of approximately 3,000,000 inhabitants, there were 15,105 Catholics and 449 catechumens. The missionary personnel, in addition to the bishop, consisted of 18 foreign priests and 9 Chinese; the auxiliary personnel included 72 sisters, of whom 60 were Chinese; 31 catechists, 13 teachers, 7 baptizers, 1 physician, and 16 nurses. In the minor seminary there were 45 students, 3 in the regional seminary at Hong Kong, and 1 at the Urban College in Rome. Within the territory, divided into 18 primary stations and 30 secondary stations, there were 10 churches and 28 chapels. The works included a hospital, 14 dispensaries, 4 orphanages, 2 homes for the elderly, 1 leper colony, and 5 elementary schools.
According to local tradition, the first missionary arrived in this region in the first half of the 17th century; evidence of Christians before 1646 is provided by some tombs found near Liuchow, while three tombs in the Catholic cemetery at Hoikow and Kiungchow, dated between 1660 and 1680—one of which bears the name of Fr. de Matha—bear witness to the presence of the Jesuits in that century. After the suppression of the Society of Jesus, only a few Chinese priests were sent periodically from Macao. In 1848, Kwangtung was entrusted to the Paris Foreign Missions, and the following year Fr. Amat arrived; he died of cholera in 1863.