YENCHOW, DIOCESE of. – In the central-southern part of the province of Shantung (northern China).
It was erected, under the name of Apostolic Vicariate of Southern Shantung, on 8 January 1886, by division of the Apostolic Vicariate of Shantung (v. TSINAN), and was the first of the missions entrusted to the Society of the Divine Word in China. On 3 December 1924 it received the present name of the city of Y. It underwent a first division on 11 February 1925 Tsingtao (v.), a second on 13 December 1933 Yangku (v.), and a third on 12 November 1934 Tsaochow (v.). On 11 April 1946 it was elevated to a suffragan diocese of Tsinan.

The Divine Word religious began their activity at Polichwang, now belonging to the mission of Yangku, where they arrived in 1882 and found a nucleus of 150 Christians. Despite the many difficulties caused by the persecution of the Boxers, the First and Second World Wars, and other local causes, the excellent preparation of the Divine Word missionaries, led by Bishops Giovanni B. von Anzer (1886–1903) and Agostino Henninghaus (1903–1936), gave vigorous impetus to the missionary movement: as of 30 June 1947, the Christians of Y., of the three missions that had arisen from it (Tsingtao, Yangku, Tsaochow), and of Ichow, which had arisen from Tsingtao, numbered 202,565. Bishop Anzer, in an attempt to bring the faith to the city of Tsaochow, was subjected to the insults of the populace incited by the authorities, then flogged until he bled and tied to a tree (1903); the same fate befell Fr. Giuseppe Freinademetz, who died in the reputation of sanctity in 1908. On 2 November 1897, in a village in the district of Küyeh, now belonging to the mission of Tsaochow, Fathers Francesco Nies and Rinaldo Henle were killed.