sentences:  However, the diocese was demoted to the Apostolic Vicariate of Kiangnan on January 21, 1856 by Pope Pius IX, and its name was later changed to the Apostolic Vicariate of Kiangsu on August 8, 1921 and to the Vicariate Apostolic of Nanjing on May 1, 1922.Pope Pius XII elevated it on April 11, 1946 to the rank of a metropolitan archdiocese, with the suffragan sees of Haimen, Shanghai, Suzhou, and Xuzhou.The archdiocese's motherchurch and thus seat of its archbishop is the Cathedral of the Immaculate Conception also known as the Shigu Road church.