Tây Thành was the former 32nd province of Nguyễn Vietnam that encompassed the region what is present-day Cambodia. Its capital was the Cambodian capital of Phnom Penh (known to the Vietnamese as "Nam Vang"). It was a special province with a dual system, consisting of Cambodian monarchs who reign as puppet rulers while a Vietnamese governor resided in Phnom Penh. The province was finally abolished in 1847 after peace talks between Thailand and Vietnam concluded a dual-suzerainty over Cambodia.