Biên Hòa province

Biên Hòa ) was a former province of Vietnam under the Nguyễn dynasty and the South Vietnam. By June 2025, the original Biên Hòa corresponded areas of Đồng Nai province, Bà Rịa–Vũng Tàu province and Bình Phước province with total area of over 17.000 km².

History

In 1698, Lord Minh ordered Lễ Thành hầu establishing Gia Định prefecture with two districts in Cao Miên territory: Phúc Long district based on Đồng Nai, protected by Trấn Biên palace; and Tân Bình district based on Sài Gòn, protected by Phiên Trấn palace.
In 1715, Phiên Trấn commander – Trần Thượng Xuyên, and Trấn Biên deputy commander – Nguyễn Cửu Phú led Gia Định forces to support Nặc Yêm in defeating Nặc Thâm and retaking the La Bích citadel. Lord Minh appointed Nặc Yêm as the new king of Cao Miên.
Biên Hòa province was first established in 1832 when Emperor Minh Mạng divided Lower Cochinchina into Six Provinces.
By the 4th year under Tự Đức, Biên Hòa contained two prefectures: Phước Long, and Phước Tuy, dividing to seven districts: Phước Chính, Bình An, Phước Bình, Nghĩa An, Phước An, Long Thành, and Long Khánh.
In 1876 it was split to Biên Hòa, Thủ Dầu Một and Bà Rịa. On October 22, 1956, it was split to Bien Hoa, Long Khánh, Phước Long, Bình Long. On May 2, 1957, it contained four districts, Châu Thành Biên Hòa, Long Thành, Dĩ An and Tân Uyên. On January 23, 1959, Tân Uyên was separated and the rest became Phước Thành province.
During Republic of Vietnam period, Biên Hòa hosted several ARVN critical bases like the III Corps Headquarters, the Long Bình Post, and the Biên Hòa Air Base.
The northernmost of Biên Hòa was also the southernmost of the Viet Cong War Zone D.