The seat of the Governor-General for the whole of French Indochina was based in Hanoi, which was situated in Tonkin (now northern Vietnam). Cambodia, being a constituent protectorate of French Indochina, was governed by the Résident Supérieur (Resident-General) for Cambodia, who was directly appointed by the Ministry of Marine and Colonies in Paris.
The Resident-General was in turn assisted by Residents, or local governors, who were posted in all the provincial centers, such as, Battambang, Pursat, Odong, and Siem Reap. Phnom Penh, the capital, was under the direct administration of the Resident-General.
The Resident-General held considerable power, but the person in the position frequently wanted more. In 1897, the ruling Resident-General complained to Paris that the current king of Cambodia, King Norodom was no longer fit to rule and asked for permission to assume the king's powers to collect taxes, issue decrees, and even appoint royal officials and choose crown princes. From that time, Norodom and the future kings of Cambodia were figureheads and merely were patrons of the Buddhist religion in Cambodia, though they were still viewed as god-kings by the peasant population. All other power was in the hands of the Resident-General and the colonial bureaucracy. Nonetheless, this bureaucracy was formed mostly of French officials, and the only Asians freely permitted were ethnic Vietnamese, who were viewed as the dominant Asians in the Indochinese Union.
In 1904, King Norodom died. Rather than pass the throne on to Norodom's sons, the French passed the succession to Norodom's brother Sisowath, whose branch of the royal family was more submissive and less nationalistic to French rule than Norodom's, who was viewed as the more nationalistic branch of the family. Likewise, Norodom was viewed as responsible for the constant Cambodian revolts against French rule. Another reason was that Norodom's favorite son, who he wanted to succeed him as king, Prince Yukanthor, had, on one of his trips to Europe, stirred up public opinion about French colonial brutalities in occupied Cambodia.
Meanwhile, the rule of King Sisowath, and his son, King Sisowath Monivong, were peaceful, even though the monarchs were nothing but puppets and pliant instruments of the French. During Sisowath's reign, the French succeeded in getting Thailand's reformist king, King Chulalongkorn, to sign a new treaty in 1907, which returned the northwestern provinces of Battambang and Siemreab back to Cambodian rule. In this sense, the Sisowath branch of the family is seen in restoring Cambodian land, even though it all passed under oppressive French colonial rule.