Created by decree 120-SL on 25 January 1948 by the Democratic Republic of Vietnam. Located in the northern delta, this zone combined Zones II, III and XI and consisted of the following provinces: Hai Phong, Kien An, Thai Binh, Hung Yen, Hai Duong, Hanoi, Ha Dong, Son Tay, Ha Nam, Nam Dinh, Ninh Binh, and Hoa Binh. It bordered Inter-Zone Viet Bac to the north and west, Inter-Zone IV to the southwest, and the sea to the east and southeast. As of April 1954, this zone consisted of four regiments, nine battalions and 58 platoons. Inter-Zone III’s first commander-in-chief was Hoang Sam while Le Quang Hoa, and then Do Muoi (the future general secretary of the Vietnamese Communist Party) served as its ranking political commissars.