Small ethnolinguistic group of North Luzon, Philippines
The Gaddang are an indigenous people and a linguistically identified ethnic group residing for centuries in the watershed of the Cagayan River in Northern Luzon, Philippines. Gaddang speakers were recently reported to number as many as 30,000, a number that does not include another 6,000 related Ga'dang speakers or any of several other small linguistic-groups whose vocabularies are determined to be more than 75% identical.
These proximate groups (speaking mutually-intelligible but phonetically varying dialects which include Gaddang, Ga'dang, Baliwon, Cauayeno, Majukayong, Katalangan, Itawit, and Yogad, as well as historically documented tongues such as that once spoken by the "Irray" of Tuguegarao) are depicted in cultural history and official literature today as a single people. Other distinctions are asserted between (a) Christian residents of the Isabela plains and Nueva Vizcaya valleys, and (b) formerly non-Christian residents in the nearby Cordillera mountains. Certain reporters exaggerate one or more of the cultural differences, while others may completely ignore or gloss them over. 
The Gaddang are Indigenous to a compact geographic area; the theatre for their story is an area smaller than three-quarters of a million hectares (extreme distances: Bayombong to Ilagan="120 km", Echague to Natonin="70 km"). The living population collectively comprises less than one-twentieth of one percent "(.0005)" of inhabitants of the Philippines, sharing one-quarter percent of the nation's land with Ifugao, Ilokano and others. 
The Gaddang cultural-identity is determined by their language and to a lesser degree was shaped by their location. As a people, Gaddang have no record of expansionism, they created no unique religion or set of beliefs, nor produced any notable government. However, they have historically implemented social mechanisms to incorporate as full members of their communities individuals born to linguistically-different peoples.
Physical geography.
Topography of north &amp; central Luzon: the "Cagayan Valley" is surrounded by mountains.
The Cagayan Valley (with tributaries "Magat", "Ilagan", "Mallig" and "Siffu" of the Mallig Plains, and "Chico" which reaches the Cagayan just 30 miles from the sea) is cut-off from the rest of Luzon by mile-high forested mountain ranges joined at Balete Pass near Baguio. If one travels south from the mouth of the Cagayan River and along its largest tributary (the Magat), the mountains become a dominant, brooding presence. The terraced Cordilleras close in from the west, the darker reaches of northern Sierra Madre arise in the east, meeting at the river sources in the Caraballo Mountains.
Once covered in continuous rainforest, today the valley-floor is a patchwork of intensive agriculture and mid-size civic centers surrounded by hamlets and small villages. Even remote locations in the surrounding mountains now have permanent farm-establishments, all-weather roads, cell-phone towers, mines, and regular markets. Often, native forest-flora has vanished, and any uncultivated areas sprout invasive "cogon" or other weeds.
The International Fund for Agricultural Development in its 2012 study on Indigenous People's Issues in the Philippines identifies populations of Gaddang (including Baliwon, Majukayong, and iYogad) in Isabela, Nueva Ecija, Nueva Vizcaya, Quirino, and Mountain Provinces.
A linguistic geography.
The Cagayan Valley is physically divided from the rest of Luzon; Cagayan Valley cultures and languages are separated from other Luzon cultures and languages by social geography. 
The homelands of the Kapampangan (2.7 million speakers) and Pangasinan (1. 8 million) lie south of the mountains between the Cagayan and the enormous Tagalog-speaking population of Central Luzon – and are themselves barred from the valley by the diverse Igorot/Ilongot peoples of the Cordilleras and Caraballos. East of the valley, Kasiguranin farmers and various "negrito" Aeta hunter-gatherers inhabit a few small communities in the Sierra and along the seashore; many Ilongot peoples live east of the valley, particularly Aurora. From the 17th through the 19th centuries, many Ilokano (now 8,000,000 worldwide) left the crowded northwest coast to labor on Cagayan Valley plantations. Today, Ilokano-speakers in the Cagayan valley outnumber descendents of the original inhabitants by many times, and these Ilokano make up the majority of the residents of the northern area of Central Luzon. 
Evidence is that Gaddang occupied this vast protected valley jointly with culturally-similar neighbors for many hundred years. The Gaddang language has similarities to those of the Itawes and Malaueg settled at the more distant mouths of the Matalag and Chico rivers, as well as the more numerous Ibanag and Isneg of the valley. Gaddang have, however recently settled in north Aurora and Baler located in Central Luzon. But even among the half-million Cagayan Valley of indigenous-descent, Gaddang count as less than 10%. 
Prior to use of a Filipino "national-language" or the official use of English dating from the early 1900s (even before the 1863 decree requiring Spanish in official life), 17th century Dominicans promulgated Ibanag as the "sole" medium for communication and education throughout the Valley. The Provincial Chapter of the Dominicans decreed in 1607: "Praecipientes ut omni studio et diligentia dent operam, ut linguam de Ibanag loquantur Yndi omnes, et in illa dictis indis ministrare studeant." In the area inhabited by Irraya-speakers (along the river from Tuguegaro to Ilagan) this policy helped Ibanag to supersede the local languages. But most Gaddang language-variants (including Yogad and Cauayan) continued to remain vital and distinct from Ibanag, a situation which persists in the southern Cagayan and Magat valleys and foothills of the Cordillera. Decades of linguistic studies document considerable identity among the Gaddangic tongues, while revealing less intelligibility with Ibanag and Isneg.
Evolving the idea of a people.
Early depictions of Filipinos were written by conquerors to serve administrative, evangelical, or military purposes. Writers ignored scientific rules of evidence, and may be unreliable about conditions. There are "no" native reporters whose work survives. Consequently, descriptions from this period are an "overlay" imposed by foreign invaders on indigenous cultures. As such, they promote the interests of church, crown, and the business of the local governing apparatus, while failing to comprehend or accurately portray native concepts.
In 1902, the US Commissioner for Non-Christian Tribes wrote: ;templatestyles src="Template:Blockquote/styles.css" / ;"One impression that has gained a foothold in regard to tribes of the Philippines I believe to be erroneous, and that is as to the number of distinct types or races and multiplicity of tribes. Owing to the fact that nowhere in the Philippines do we encounter large political bodies or units, we have a superlative number of designations for what are practically identical people...For example, among the powerful and numerous Igorot of Northern Luzon, the sole political body is in the independent community. Under normal conditions, the town across the valley is an enemy and seeks the heads of its neighbors...Sometimes three or four different terms have been applied by different towns to identical peoples."
So, there was no "Gaddang people" prior to the Spanish incursion; merely inhabitants of evanescent forest hamlets having tenuous relationships to people in similar settlements. Customs and language might be shared with neighbors, or they might not – the Spanish visitors created whole peoples from such tiny gatherings. Nonetheless, we find the folk named long ago as Gaddang still residing in the same locales and using the same family names as were written down more than four hundred years ago.
At the end of the Spanish period, Fr. Julian Malumbres was writing his "Historia de Nueva-Vizcaya y Provincia Montanõsa" (published after the American takeover), which carefully details the doings of the individual priests, administrators, and military persons throughout the several hundred years of the occupation. He is fairly vague about actions and customs of the native population.
American businessman Frederic H. Sawyer lived in Central Luzon beginning in 1886. He compiled "The Inhabitants of the Philippines" from official, religious, and mercantile sources during the last years of the Spanish administration. Published in 1900, it was intended to be a resource for incoming Americans. His descriptions are meager and at best secondhand. In his section titled "Gaddanes" we recognize the pagan residents of the highlands. The residents of Bayombong, Bambang, Dupax, and Aritao, however, are called "Italones", while their like in Isabela are the "Irayas" and the "Catalanganes". These very terms are shown on military maps used by General Otis and his staff during the Philippine–American War.
In 1917, respected University of the Philippines ethnologist/anthropologist H. Otley Beyer reported 21,240 "Christian" Gaddang ("civilized and enjoying complete self-government") and 12,480 "Pagan" Gaddang ("semi-sedentary agricultural groups enjoying partial self-government). In this text, Beyer specifically notes that the Gaddang language ""is divided into many dialects", and that all groups have a "marked intonation while speaking"". He enumerated the Christian group as 16,240 Gaddang-speakers and 5,000 Yogad-speakers. Some Pagan Gaddang spoke Maddukayang/Majukayang (or Kalibungan) – a group totalling 8,480 souls. There were also 2,000 whose language was Katalangan (an Aeta group farming the foothills of the Sierra Madre in San Mariano, described in 1860 by naturalist Carl Semper), and another 2,000 speaking "Iraya.").
A 1959 article by Fr. Godfrey Lambrecht, CICM is prefaced: ;templatestyles src="Template:Blockquote/styles.css" / ;"(The Gaddang) are the "naturales" of the towns of Bayombong, Solano, and Bagabag, towns built near the western bank of the Magat river (a tributary of...the Cagayan River) and of the towns of Santiago (Carig), Angadanan, Cauayan, and Reyna Mercedes... "
"According to the census of 1939, the pagan Gadang numbered approximately 2,000, of whom some 1,400 lived in the outskirts of Kalinga and Bontok subprovinces... and some 600 were residing in the municipal districts of Antatet, Dalig, and the barrios of Gamu and Tumauini. Dalig is ordinarily said to be the place of origin of the Christianized Gadang. The same census records 14,964 Christians who spoke the Gadang language. Of these 6,790 were in Nueva Vizcaya, and 8,174 in Isabela. Among these, there were certainly some 3,000 to 4,000 who were not "naturales" but Ilocano, Ibanag, or Yogad who, because of infiltration, intermarriage, and daily contact with the Gadang, learned the language of the aborigines."
The 1960 Philippine Census reported 6,086 Gaddang in the province of Isabela, 1,907 in what was then Mountain Province, and 5,299 in Nueva Vizcaya. In the 1980s - using this data - Mary Christine Abriza wrote:
 ;templatestyles src="Template:Blockquote/styles.css" / ;"The Gaddang are found in northern Nueva Vizcaya, especially Bayombong, Solano, and Bagabag on the western bank of the Magat River, and Santiago, Angadanan, Cauayan, and Reina Mercedes on the Cagayan River for Christianed groups; and western Isabela, along the edges of Kalinga and Bontoc, in the towns of Antatet, Dalig, and the barrios of Gamu and Tumauini for the non-Christian communities. The 1960 census reports that there were 25,000 Gaddang and that 10% or about 2,500 of these were non-Christian."
In April 2004, the National Statistics Office published a "Special Release" outlining results of the "2000 Census of Population and Housing in the Philippines". In those administrative regions with the largest concentrations of indigenous residents, Region II (10.5% of the nationwide indigenous population, Cagayan Valley IPS were 23.5% of all Region II residents), and the Cordillera Autonomous Region (CAR was home to 54.5% of all Philippine IPS, who comprised 11.9% of the CAR population). Gaddang and Yogad were among the 83 groups identified as IPs.
History.
Material specifically relevant to the Gaddang (even when semi-distinct groups like Cauayeno and Yogad are included) over the past millennium is meagre. Today's Gaddang-identity has survived invasion, colonialism, suppression, assimilation, and nationalism. Important parts of the Gaddang story was lost to colonial suppression, the ravages of armed-conflict, careless or disinterested record-keeping/maintenance during inconstant administrations, and lack of documentary ability or interest among the historic population. The extant historical data (property-records, parish vital statistics, &amp;c.) are granularly-concerned with specific places and events, or are descriptive of developments affecting large areas and populations. But such records do provide "context" and "continuity" for understanding the sporadic appearances of Gaddang peoples.
Pre-history.
Archeologists working in Peñablanca date the presence of humans in the Cagayan Valley as early as one-half million years ago. Around 2000 B.C., Taiwanese nephrite (jade) was being worked along the north coast of Luzon and in the Batanes, particularly at the Nagsabaran site in Claveria, although this international industry had moved to Palawan by 500 CE.
Subsequent prehistory of Luzon is subject to significant disagreements on origins and timing; genetic studies remain inconclusive as of 2024[ [update]]. Generally agreed, however, is that a series of colonizing parties of Austronesian peoples arrived from 200 B.C. to 300 A.D. along the northern coasts of Luzon, where the river valleys were covered with a diverse flora and fauna. They found the Cagayan River bottoms sparsely occupied by long-established Negrito Aeta/Arta peoples, while the hills had