The Isnag people (also referred to as Isneg and Apayao) are an Austronesian ethnic group native to Apayao province in the Philippines' Cordillera Administrative Region. Their native language is Isneg (also called Isnag), although most Isnag also speak Ilocano.
Two major sub-groups among the Isnag are known: the Ymandaya, mostly concentrated in the municipality of Calanasan; and the Imallod, with populations distributed among the other towns of the province. Isnag populations can also be found in the eastern part of the adjacent provinces of Ilocos Norte and Cagayan.
Various names have been used to differentiate the Isnag. The Spaniards referred to them as los Apayaos (referring to the river along which they live) and los Mandayas (taken from the Isnag term meaning “upstream”). In 1923, they were the last ethnic group to be conquered by the American colonialists. Before, they had no collective name. Instead, they referred to themselves based on their residence or whether they lived: upstream (Imandaya) or downstream (Imallod). At present, they are commonly known as Isnegs, which came from an Ilocano word itneg that means Inhabitants of the Tineg River. Some of them, however, still call themselves as Apayaos.
The Isnegs are native in Apayao province, which was formerly a sub-province of Mountain Province, but are also found in portions of Abra, Ilocos Norte, & Kalinga. Apayao has an area of 397,720 hectares and is typographically divided into two parts: the Upper Apayao that is mountainous, and the Lower Apayao that is generally flat with rolling mountains and plateaus. Today, there are about 40,000 Isnegs living in Apayao. Isnag populations can also be found in the Eastern part of the Province of Ilocos Norte, specifically the municipalities of Adams, Carasi, Dumalneg and Solsona; and in the Northwestern part of the Province of Cagayan, specifically the municipalities of Sta. Praxedes, Claveria and Sanchez Mira. The majority of them live along the Apayao River-Abulog River, Matalag River, and the small rivers on the hillsides of Ilocos Norte and Abra.