Hung Hoa diocese, Vietnam's largest diocese in terms of area, borders China and Laos. It covers 48,072 square kilometers and includes the whole provinces of Dien Bien, Lai Chau, Lao Cai, Phu Tho, and Son La, as well as parts of Ha Giang, Ha Tay, Hoa Binh and Tuyen Quang provinces. It is a suffragan diocese within the ecclesiastical province of Ha Noi.
Hung Hoa diocese was established on April 15, 1895. Bishop Paul Marie Raymond Loc of the Paris Foreign Mission Society (MEP) was ordained its first bishop on Oct. 15 that same year. Bishop Paul Nguyen Huy Quang, Hung Hoa's first Vietnamese bishop, was head of the diocese from 1960 until he died in 1985.
The diocese is estimated to have 39 ethnic peoples, but only 16 have been officially recorded. Besides Kinh (majority Vietnamese), who account for 85 percent of the total, there are 15 ethnic peoples, including Bo Y, Dao, Day, Ha Nhi, H'mong, Kho Mu, La Chi, Lao, Muong, Nung, Phu La, San Chay, San Chi, Thai and Tay.