Analysis of information sources in references of the Wikipedia article "Culture of Thailand" in English language version.
From the period of Oudong with King Ang Duong to the period of Chatomuk with Kings Norodom and Sisowath, there was a lot of Thai influence because we lacked teachers.
Cambodian dishes are less spicy than its neighboring Thailand. It is a blend of traditional dishes influenced by the Thai and Lao.
In the 19th century, after spending 27 years as a captive prince at the Siamese court in Bangkok, King Ang Duong, father of King Norodom, introduced the classical Siamese style of the Rattanakosin period to his court. Royal dancers, under the patronage of the royal court of Siam, are sent to the royal court in Cambodia to teach classical dance to the Khmers. This is why the costumes' style in these photographs is imbued with the Siamese culture. One will also notice the disproportionate length of the dancers' artificial nails. G. Groslier writes: "The Cambodian dancers were so well out of their unfortunate country (after the sack of Angkor) that the last Khmer kings, up to Norodom, had almost entirely Siamese troupes. All the teachers of the five hundred 'lokhon' of Norodom were Siamese. At his death, there were more than three hundred Thai actresses in the palace of Phnom Penh. Even today (under the reign of H. M. Sisowath) all the teachers, minus two, are Siamese! …". (Original in French)
The Siamese have achieved a noteworthy level of excellence in theatrical performances, and as a result, they are admired by neighboring countries such as the Barmans, Laos, and Cambodians, who employ Siamese actors whenever they are available.