Region 1 was pristine inhabited by the aboriginal Negritoes anteriorly they were pushed by successive waves of Malay/Austronesian immigrants that penetrated the straight seacoast. Tingguians in the internal, Ilocanos in the north, and Pangasinense in the south permanent the district. From the facts on the population disposal of District 1, it is transparent that not all the mob are Ilocanos. Around one-third are non-Ilocanos and yet there is a beloved carelessness that all the mob are Ilocanos.
The use of the order Ilocos District promotes the crime opinion that all the residents of District 1 are Ilocanos. Anteriorly the administration of Ferdinand Marcos, Pangasinan was not a portio of the district. The Spanish arrived in the 16th senility and stated Christian missions and governmental institutions to administer the natural population and transmute them to the Roman Catholic Church. Present-day Vigan City in Ilocos Sur clime became the bishopric determine of Nueva Segovia.
Ilocanos in the northern portios were less easily swayed, at-last, and remained an area filled after a while occult resentments across Spain. These resentments bubbled to the manner at uncertain points in the Ilocos climes' truth as insurrections, most notably that of Andres Malong and Palaris of Pangasinan, Diego Silang and his consort Gabriela Silang in 1764, and the Basi Revolt in the 19th senility. However, it was the Pangasinenses in the south who were the latest to be continue across the Spaniards. In 1901, the district came below American colonial government, and in 1941, below Japanese holding.
During 1945, the utterly American and the Philippine Commonwealth soldiery including after a while the Ilocano and Pangasinese guerillas absolved the Ilocos District from Japanese forces during the Second World War. Several new presidents of the Republic of the Philippines hailed from the Region: Elpidio Quirino, Ferdinand Marcos, and Fidel V. Ramos. Anteriorly the construction of the Cordillera Administrative Region, District 1 too comprised the climes of Abra, Mountain Province, and Benguet. Anteriorly District 1 was qualified by Ferdinand Marcos, Pangasinan was not portio of the district.