The Khiamniungan tribe is one of the major tribes among the Nagas, with habitation both in India and Myanmar. Geographically, the land of Khiamniungans is located in the Eastern part of Nagaland and in the North-Western part of Myanmar. The nomenclature of the tribe ‘ Khiamniungan’ is a compound word formed by three words: ‘Khiam’ means water, ‘Niu’ means great and ‘Ngan’ means source. Thus, the meaning of the term Khiamniungan is ‘source of great water or river’. The nomenclature derives from the biggest river of the land (laang) and to the river to which it ultimately confluence (Chindwin). Some earlier written sources wrongly referred to the Khiamniungans as ‘Kalyo-Kengnyu’ named after the snow-clad mountain of patkoi ranges locally known as Khulioking. According to 2011 census, the total population of the Khiamniungan tribe is 61,983. The ISO code is 639-3. 

According to a popular myth, Khiamniungan means “source of mighty water” – the place from where the early ancestors of Khiamniungan are said to have originated. This place is identified near Lengnyu-Tsuwao villages, under Patsho Range, overlooking the present-day Patsho and Noklak towns.

Tsokum is one of the most important and significant festivals which is celebrated with great pomp and gaity. Tsokum Sumai is celebrated in the month of September or in the first past of October to invoke blessing for a rich harvest. During Tsokum Sumai, each and every family offer prayer and make sacrifices by killing domesticated animals to the gods (Ko-a) for fertility of crops, bountiful harvest, to bless their livestock and grant good health to human beings as well. Tsokum is the festival of dedication to commence the harvest in the jhum field. 

Khaotzao Sey Hok-ah sumai (Festival) is another important festival of Khiamniungan Naga which marks the end of all agricultural activities for the year, a time to rest and give thanks to god for the bountiful harvest and triumph over adversities all throughout the year.

Khaotzao Sey Hok-ah is a combination of four word; the word ‘Khaotzao’ refers to bamboo container (mug)used for drinking rice beer, ‘sey’ means preparation of rice beer inside a large container made of bamboo, ‘hok’ means leg and ‘ah’ means rest. Thus in short ‘Khaotzao Sey Hok-ah’ means festival of rest and feast with abundance of rice beer. It is celebrated in the month of January (Hok-ah lei).