The Khmers belonging to the Mon-Khmer ethnic group are the oldest inhabitants of the Indochinese peninsula. The origins of their civilization can be dated from between one million and 680.000 years ago , having evolved since from generation to generation to form an elaborate specific cultural mode .Cambodian history is divided into two periods: the prehistoric and historic eras. Each period is also divided into different ages. The prehistoric era consists in the Paleolithic Age, including the Pebble Culture,the Neolithic (polished stone), and Metal ages. Similarly, the historic period is divided into three parts: the Ancient, Middle and Modern epochs.During the prehistoric period between one million and 680.000 to the 1st century B.C, the populations were ignorant of writing and then did not know how to record the story of their religion, economy, and politics. They only relied upon oral tradition.. This is still the case with the Khmer hill tribes such as the Phnong and the Tampoung .Differing from the prehistoric era, the second period of Cambodian history began in the first century AD. During that time, under Indian influence,writing appeared, allowing to record the historic events of the Khmer people , but writing and reading was not popular knowledge , being the prerogative of the rulers only.The history of the Kingdom of Cambodia is more than 2000 years old. Similarly, the use of Khmer inscriptions also originates from that era even though during the early historic period, literacy was not common..We shall note that the inscriptions are not only a tool to record events , but also a vehicle for promoting the religious doctrine and the key to strengthening the power of the kings or rulers.Thus the ruling by the law and the propagation of the Hindu and Buddhist faiths that was implemented by the authorities from the 1st to the 7th century were not only aimed at the urban people, but was also intended for all the kingdom. Thus writing has been the key to unity. (M.Tranet).