Nguyễn Phúc Chu was one of the Nguyễn Lords who ruled south Vietnam from the city of Phu Xuan (modern-day Huế). During his time in power he had to deal with a Champa rebellion and the first major war against the Cambodians.
Nguyễn Phúc Chu was the eldest son of Nguyễn Phúc Trăn. He gained the throne on his father's early death, at just 15 years old. He took for himself the title Tong Quan-Cong (Duke of Tong).
Early in his reign the Champa ruler of Panduranga (in present-day Ninh Thuan province), Po Sot, started a rebellion against the Nguyễn. The revolt was at first unsuccessful and after the Nguyễn army put down the revolt there was an outbreak of plague in Panduranga. Three years later, a Cham aristocrat, Oknha Dat, obtained the help of General A Ban (a somewhat mysterious figure). Together they defeated a Nguyễn military force in 1695. The new Champ king, Po Saktiray Da Patih (younger brother of Po Sot), made a treaty with Nguyễn Phúc Chu. The result was the Cham rulers in Panduranga were recognised as Trấn Vương (local lords) for the next 135 years, though they had no authority over Vietnamese living in the area.
In 1714 Nguyễn Phúc Chu sent an army into Cambodia to support Keo Fa who claimed the throne against Prea Srey Thomea (see also the article on the Dark ages of Cambodia). The army of Siam also got involved in the war, the Siamese sided with the Prea Srey Thomea against the Vietnamese (this was during the time of the Ayutthaya Kings of Siam). The Vietnamese won several battles against the Siamese (including the battle of Bantea Meas) but towards the end of 1717 they were losing. The war ended with negotiations and the Nguyễn government gained Gia-Dinh (?) and Ha-Tien (?) around the Mekong river.
Nguyễn Phúc Chu persecuted Catholic missionaries and tripled the taxes on Christians in his lands.
In 1720, near the end of his reign, Nguyễn Phúc Chu, took formal control over the last lands of the Champa. Whether this was a violation of the peace treaty he signed with the Cham 25 years earlier is not known.