The Lao-Tai, or tribal Tai, include the Black Tai and Red Tai (so-called in reference to the colour of their women's dress), who live throughout the country, especially at higher elevationsThe Lao-Toong speak Mon-Khmer based languages, and are often termed the Austro-Asiatic people, (the largest group being the Kammu). These peoples are thought to be the descendants of the earliest peoples of the region; they live throughout Laos and in neighbouring countries, and their settlements are usually situated on the slopes at moderate elevations, and this pattern may have been due to immigration pressure by the early Lao who eventually took over the valleys. The Lao-Soong group, including the Hmong (Meo, or Miao) and the Man (Yao), probably migrated from southern China to Laos in the late 18th century, and live in the mountains at the highest elevations, since most other land spaces had already been occupied at the time of their arrival. Each of these groups, and the divisions within them, have their own culture, but in this website most of the focus is on lowland Lao culture.