According to a 1983 census, the Red Karens (Karenni) consist of the following groups: Kayah, Geko (Kayan Ka Khaung, Gekho, Gaykho), Geba (Kayan Gebar, Gaybar), Padaung (Kayan Lahwi), Bres, Manu-Manaus (Manumanao), Yintale, Yinbaw, Bwe, Shan and Pao. Several of the groups (Geko, Gebar, Padaung) belong to Kayan, a subgroup of Red Karen.
The Karenni States is the name formerly given to a group of states, located south of the Federated Shan States and east of British Burma, ruled by petty princes styled myoza. These included Kantarawadi (3,161 square miles or 8,190 square kilometres, pop (1931) 30,677; the only one whose ruler promoted to saopha (sawba)), Kyebogyi (790 square miles or 2,000 square kilometres, pop (1931) 14,282), Bawlake (568 square miles or 1,470 square kilometres, pop (1931) 13,802), Nammekon and Naungpale.
The British government recognized and guaranteed the independence of the Karenni States in an 1875 treaty with Burmese King Mindon Min, by which both parties recognized the area as belonging neither to Burma nor to Great Britain. Consequently, the Karenni States were never fully incorporated into British Burma. The Karenni States were recognized as tributary to British Burma in 1892, when their rulers agreed to accept a stipend from the British government. In the 1930s, the Mawchi Mine in Bawlake was the most important source of tungsten in the world. The Constitution of the Union of Burma in 1947 proclaimed that the three Karenni States be amalgamated into a single constituent state of the union, called Karenni State. It also provided for the possibility of secession from the Union after 10 years. In 1952, the former Shan state of Mong Pai was added, and the whole renamed Kayah State, possibly with the intent of driving a wedge between the Karenni (in Kayah State) and the rest of the Karen people (in Karen State), both fighting for independence.