King Norodom was born in 1834; the eldest son of King Ang Duong; half-brother of prince Si Votha and King Sisowath. He was educated in Bangkok, Siamese capital, where he studied Pali and Sanskrit Buddhist scriptures and the sacred canons of Theravada Buddhism. The purpose of his early training was to strengthen ties between Siam (Thailand) and Cambodia.
Cambodia had been under the joint vassalage of Vietnam and Siam since 1802. According to established protocol, Cambodian kings were crowned jointly, with representatives of the two suzerains attending. When King Ang Duong died in 1860, Norodom was chosen the successor, but he remained uncrowned.
In 1860 and 1861 the Cambodian royal family came close to totally destroying itself. The country was torn by rebellion; not only were there the partisans of Norodom and Si Votha, but also other rebel groups and bandits. Sisowath, without openly avowing his sissidence, did nothing to help Norodom. Before the end of 1861, Nordom abandoned the capital of Oudong, and in 1862 he fled to Bangkok.
The French forced Norodom to accept French protection; a Protectorate Treaty was established on August 11, 1863. It required King Norodom to hand over the kingdom's foreign relations to France, prohibited the king from receiving any foreign consuls without French permission. In return, France pledged to give protection to the Khmer kingdom, recognized the sovereignty of the king, and to assist in maintaining internal order as well as in protecting the country against external attack.
The treaty was ratified by the French's parliament on January 22, 1864. However, before the agreement was ratified in Paris Norodom secretly signed a treaty with Siam in December 1863 that completely undermined the provision of the French imposed agreement. It made Norodom the viceroy of Siam and governor of Cambodia; Siam acquired the Cambodian provinces of Battambang and Siem Reap.
In an attempt to show that Norodom was nothing more than a Siamese governor and must be crowned in Bangkok, the Siamese court refused to release the Cambodian royal regalia (the crown, the sacred sword, and royal seal) to Oudong, Khmer court. Despite the French warning of unpleasant consequences, on March 3, 1864 Norodom decided to travel to Bangkok. The French representative acted swiftly by occupying the Khmer court and hoisted the French flag. Norodom turned back, accepting the supremacy of the French. He was finally crowned on June 3, 1864 at Oudong, with both French and Siamese representatives in attendance.
Throughout King Norodom reign the French increased their domination of Cambodian affairs. They imposed upon King Norodom land reforms, a reorganization of Cambodian military forces, and the abolition of slavery.
By early 1884 the French took over the collection of taxes on opium and alcohol sold in Cambodia. On June 17, 1884 King Norodom was forced to sign a convention of sweeping reform of the Kingdom. It required the King to accept all the administrative, judicial, financial, and commercial reforms; the French reserved the right to further reform; the French would appoint its own "Residents" to provinces to control the administration of Cambodian officials. The date of the convention signed is considered the date in which Cambodia became French's colony.
From 1885 to 1886, Cambodia revolted against the French authority throughout the country, in which the French blamed King Norodom of inciting the rising. The revolt ended only when the French offered concessions to King Norodom. Under the concession, King Norodom should have full power to pardon and punish those took part in the revolt, the French should limit the number of residents to be installed in provinces and that Cambodian handled its own provincial administration, the King would appoint his provincial governor, and as a final demand he asked that no land should be alienated without his consent. In return the King was expected to bring an end to the insurgency by January 1887.
For the remaining of his reign, King Norodom tried unsuccessfully to prevent changes in his kingdom. His adherence to traditional behavior and values was demonstrated time and again in confrontations with the French. However, because of the basic weakness of his bargaining position, the French always get what they wanted. The resistance that followed the signature of the June 1884 convention, with which King Norodom was almost certainly involved, represented the one real attempt to match force with force. In later years, increased French power and the readiness of senior Cambodian officials to join their fortunes with the French undermined the King's position.
The King died on April 25, 1904; his body was cremated in January 1906.