The province of Isabela used to be a vast rainforest where numerous indigenous ethnolinguistic groups lived. Many of the same ethnic groups still live in the province.
Shell midden sites and other archaeological sites throughout the province constitute the material culture of those groups during the classical era.
Spanish colonial period Tumauini Church During the Spanish era, prior to 1856, the
Cagayan Valley was divided into only two provinces:
Cagayan and
Nueva Vizcaya. The Province of Cagayan at that time consisted of all towns from
Tumauini to
Aparri in the north. All other towns from
Ilagan southward to
Aritao composed the Province of the old
Nueva Vizcaya. In order to facilitate the work of the
Catholic missionaries in the
evangelization of the
Cagayan Valley, a
royal decree was issued on May 1, 1856, creating the Province of Isabela consisting of the towns of
Gamu,
Old Angadanan (now
Alicia), Bindang (now
Roxas) and Camarag (now
Echague), Carig (now
Santiago City) and
Palanan, all detached from the Province of
Nueva Vizcaya; while
Cabagan and
Tumauini were taken from the Province of
Cagayan. The exception is Palanan, which was established in 1625 by Spanish forces who arrived by ship from the Pacific coastal town of
Baler in Tayabas province (now part of Aurora). Thus, Palanan was originally a part of
Pampanga, then to
Laguna, Tayabas (now
Quezon Province; Tayabas became independent from Laguna), and
Nueva Ecija, before being transferred to Nueva Vizcaya and finally Isabela. Also, unlike the rest of Cagayan Valley, it was served by Franciscan missionaries from Baler rather than the Dominicans. The population of the town was natively Paranan, then subsequently augmented by local Negritos, migrants from Baler who are
Tagalogs and outlaws from Cagayan Valley, with the lingua franca of the settlement being Tagalog as opposed to Ilocano or Ibanag. The province was placed under the jurisdiction of a
governor (Lieutenant Colonel of Cavalry Francisco Contreras y Urtasun) with Ilagan as the capital, where it remains up to present. It was initially called
Isabela de Luzón and also
Isabela del Norte During that time, the Spanish controlled only the areas along the Cagayan River, leaving the Mallig Plants, the Magat River and the Sierra Madre Mountains to
Gaddang tribes. The
Atta or
Negritos were the first people in valley. They were later moved to the uplands or variably assimilated by the Austronesians, from whom the
Ibanags,
Itawes, Yogads, Gaddangs, Irayas, Malawegs, and Paranans descended - who actually came from one ethnicity. These are the people found by the Spaniards in the different villages along the rivers all over Cagayan Valley, including present Isabela. The Spaniards rightly judged that these various villagers came from a single racial stock and decided to make the
Ibanag language the
lingua franca, both civilly and ecclesiastically for the entire people of Cagayan which they called collectively as the
Cagayanes which later was transliterated to become
Cagayanos. Various other peoples, mainly the
Ilocanos,
Pangasinenses,
Kapampangans and
Tagalogs, as well as
Visayans,
Moros,
Ivatans, and even foreigners like the Chinese, Indians, Arabs, Spaniards and others were further infused to the native Cagayanes to become the modern
Cagayano, and
Isabeleño in the exact province, that we know today. During the 1818 Spanish census, Gamu (Isabela Province) had 586 native families living in harmony with 16 Spanish-Filipino families.
American colonial era Although the province did not play a major role in the revolt against Spain, it is in
Palanan that the final pages of the
Philippine Revolution were written when United States troops, led by General
Frederick Funston, finally captured General
Emilio Aguinaldo on March 23, 1901. To commemorate this historical event, in 1962 the town officials constructed a monument by the Palanan City Hall, right on the spot where General Aguinaldo was captured, to memorialize the historic event. The monument was inaugurated on June 12, 1962, Philippine Independence Day, and still stands. Isabela was re-organized as a province under the
American military government through
Act No. 210, passed August 24, 1901. The Americans built schools and other buildings and instituted changes in the overall political system. However, the province's economy remained predominantly agricultural, with rice replacing corn and tobacco as the principal crop.
Japanese occupation World War II stagnated the province's economic growth but it recovered dramatically after the war. In 1942,
Imperial Japanese forces occupied Isabela. In 1945, the liberation of Isabela commenced with the arrival of the
Philippine Commonwealth troops under the 11th Infantry Regiment, Philippine Army, USAFIP-NL and the recognized guerrillas attacked by the Japanese Imperial forces in World War II. A new wave of immigration began in the late 19th and 20th centuries with the arrival of the
Ilokano who came in large numbers. They now constitute the largest group in the province, and it was only in this large-scale Ilocano immigration & settlement that made Ilocano language replaced Ibanag as the
lingua franca of the province. Other ethnic groups followed that made Isabela the "Melting Pot of the Northern Philippines". So when the
Communist Party of the Philippines (CPP) was established in 1968 after splitting from the largely-defeated old Communist Party (
Partido Komunista ng Pilipinas-1930), Isabela became one of the first strongholds of its armed wing, the
New People's Army. The actual size of the NPA at the time was very small, reportedly with only 60 guerrillas and 35 WWII-era guns as of 1969. But Marcos hyped up its formation, supposedly because this would help build up political and monetary support from the US. The Armed Forces had a number of initial successes against the NPA in Isabela at this time, including the discovery of the Taringsing Documents in
Cordon outlining plans for a communist takeover; and the failed landing of arms bound for the NPA in
Palanan during the
MV Karagatan incident in 1972. These incidents were cited as some of the justifications for the declaration of
Martial Law by Marcos later that year. With only a year left in his last constitutionally allowed term as president Ferdinand Marcos placed the Philippines under
Martial Law in September 1972 and thus retained the position for fourteen more years. This period in Philippine history is remembered for the Marcos administration's record of
human rights abuses, particularly targeting political opponents, student activists, journalists, religious workers, farmers, and others who fought against the Marcos dictatorship. Two of the major detention centers for political detainees located in Isabela were
Camp Melchor F. dela Cruz in Barangay Upi in
Gamu, in which officers of the Armed Forces Northern Luzon Command were also stationed; renamed Camp Lt. Rosauro Toda Jr. in 2020. The province of Isabela became a particular center of both conflict and protest when
Marcos cronies Danding Cojuangco and Antonio Carag managed to block a Spanish-era grant which was supposed to see the return of Hacienda San Antonio and Hacienda Santa Isabel in Ilagan to local farmers. Cojuangco and Carag purchased the two haciendas themselves, displacing tens of thousands of farmers who were supposed to get those lands back a hundred years after the Spanish acquired them. In its desire to serve its parishioners, the
Roman Catholic Diocese of Ilagan hosted a Social Action Center which would help the farmers. In the Social Action Center's newsletter, the "Courier," researcher Sabino Padilla Jr. documented and exposed the ways by which Cojuangco, Carag, the provincial government, and the military harassed the farmers who were supposed to get the land. This all led to a protest march in joined by 12,000 protesters from all over Isabela, and eventually, for 4,000 farmers to finally get the titles to their land. But it also earned the ire of the administration. In 1985, three councilors from Barangay Ibujan in the municipality of
San Mariano, including
Ibanag community leader Luis Gabriel who had rejected overtures for the establishment of a local
CHDF base in the town, were forcibly taken by heavily armed men who claimed that they needed the three as guides. However, the three were never seen again, and they eventually became counted among the many
desaparecidos during the Marcos dictatorship. It was also during the dictatorship that Marcos began awarding logging concessions to his cronies in the areas of the Sierra Madre region, which heralded the beginning of widescale deforestation and other environmental problems that affect the province since then, despite Marcos creating the Palanan Wilderness Area in 1978 which was later expanded by President
Fidel V. Ramos to become the
Northern Sierra Madre Natural Park in 1997. In 1975, construction began on the Magat Dam on the boundary of
Ramon, Isabela with neighboring
Ifugao Province, becoming a catchbasin for 8 rivers upstream in Ifugao and serving multiple functions, including: irrigating of agricultural lands; flood control; and power generation. The construction was protested by the
Ifugao people due to the flooding of their ancestral lands, but the dam was eventually completed in 1982, partially funded through a loan from the
World Bank. After the
People Power Revolution in 1986, many of the activists who had joined the underground movement decided to "surface," as the new administration of Corazon Aquino released political prisoners and initiated peace talks. However, anticommunist sentiment in her new cabinet made the peace process difficult, and negotiations eventually collapsed, and the insurgency in Isabela persisted.
Contemporary Following the
1986 People Power Revolution, known as the current Fifth Philippine Republic, under the
1987 Philippine Constitution, various changes have been attempted since then in the province. Dy Sr. was succeeded by his son,
Benjamin G. Dy, in the gubernatorial seat from 1992 to 2001. Another Dy took over the gubernatorial seat in 2001 when Faustino Dy Jr. won the
2001 elections after having served as the district representative of the 2nd Legislative District of the province from 1992 to 2001. It was only in the
2004 elections that the family's control of the gubernatorial seat ended when
Grace Padaca, a former journalist, won over Faustino Dy Jr. She was the first woman to serve as the governor of the province. After serving for six years (2004-2010), Padaca was defeated in the 2010 National Elections by
Faustino "Bojie" G. Dy III who served as governor of the province for three consecutive terms (2010-2019). He was then succeeded by
Rodolfo "Rodito" Albano III, a member of the Albano dynasty that dominates
Isabela's 1st congressional district. In July 1994, the municipality of
Santiago was converted into an independent-component city by virtue of
Republic Act 7720. In February 1998, the
Republic Act 8528 was enacted which amended certain sections of the
Republic Act 7720 causing Santiago to be a component city in the province of Isabela. However, in September 1999 through
court ruling which granted the petition to declare
Republic Act 8528 unconstitutional, hence, the status of Santiago was reverted back to independent-component city, due to lack of plebiscite.
Santiago is geographically located in Isabela but not under the administration of the province. Its electorates are prohibited to participate in the provincial-level elections except in the 4th legislative district of Isabela where the city belongs for congress representation. In June 1995,
Republic Act 7891 was passed, legislating that Isabela be divided into two new provinces: Isabela del Norte and Isabela del Sur. A referendum was held on the same year with a slight majority voting against
partitioning the
province. In 1999, the municipality of
Ilagan, also serving as the capital town of the province, sought to become a city by virtue of
Republic Act 8474. The plebiscite held on March 14, 1999, turned down its first bid for cityhood. The majority of the people voted
no in that event. In its second attempt to achieve cityhood, the campaign did not go through due to lack of concurrency in the
senate in 2006. Finally,
Ilagan became a city, after its third move gained 96% of the votes in a plebiscite conducted on August 11, 2012. The night after the plebiscite, Ilagan was declared as a component city in the province by virtue of
Republic Act 10169. In 2001, the municipality of
Cauayan became a component city in the province of Isabela through the ratification of
Republic Act 9017. In 2019, the province was reorganized into six districts, thereby increasing the number of legislative districts from four to six. Cities and municipalities were retained and others were reapportioned to the current district assignments.
2020 Ulysses Flood Cagayan has been heavily impacted by changing weather pattern changes resulting from climate change, with the 2020 Ulysses flood being counted as one of the most severe examples. In November 2020,
Typhoon Vamco (locally known in the Philippines as Typhoon Ulysses) crossed the country, dams from all around Luzon neared their spilling points, forcing them to release large amounts of water into their impounds including Magat Dam. The dam opened all of its 7 gates at , releasing over 5,037 cubic metres (1,331,000 US gal) of water into the Cagayan River flooding numerous riverside towns. Because there was very little media coverage of the flooding in the area in the wake of the
COVID-19 lockdown in Luzon and the
Shutdown of ABS-CBN broadcasting earlier that year, residents resorted to social media to request the national government for rescue. As a result of the catastrophe, the National Irrigation Administration (NIA) indicated that it would review its protocols regarding the release of water in Magat Dam and improve its watershed. ==Geography==