Khmu were slaves of Lao noblemen and they have lived in the Southeast Asian region for over 5,000 years before the Cham, Tai and Lao settled in this area. Khmu is categorized in the Mon-Khmer language family. However, when they come into contact with lowlanders, they tend to conceal their ethnic identity and become assimilated into the mainstream cultures. Ethnic identity and culture are still maintained among those living in remote and mountainous regions of Laos. Many of them have become Buddhists or Christians, deserting their animistic practices.