Isabela is province of the Philippines, the second largest province in the country next to Palawan. It is located in the Cagayan Valley Region of Luzon. Its capital is Ilagan and borders, clockwise from the south, Aurora, Quirino, Nueva Vizcaya, Ifugao, Mountain Province, Kalinga, and Cagayan. This primarily agricultural province is the rice and corn granary of Luzon due to its plain and rolling terrain. In 2012, the province was declared as country's top producer in corn with 1,209,524 production.
It is the 10th richest province in the Philippines recorded last 2011, being the only province of Northern Luzon to be included in the list. The province has four trade centers in the cities of Ilagan, Cauayan, Santiago and the municipality of Roxas.
Prior to 1856, there were only two provinces in the Cagayan Valley: Cagayan and Nueva Vizcaya. The Province of Cagayan at that time consisted of all towns from Tumauini to the north in Aparri and all other towns from Ilagan City, Roxas southward to Aritao comprised the Province of old Nueva Vizcaya. In order to facilitate the work of the Catholic missionaries in the evangelization in the Cagayan Valley, a royal decree was issued on May 1, 1856 that created 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 Nueva Vizcaya; while Cabagan and Tumauini were taken from the Cagayan province. The province was put under the jurisdiction of a governor with the capital seat at Ilagan City, where it remains at the present. It was initially called Isabela de Luzon to differentiate from other places in the Philippines bearing the name of Isabela. The new province was named in honor of Queen Isabella II of Spain.
Although the province did not play a major role in the revolt against Spain, it is in Palanan that the final pages of the Philippines Revolution was written when the American forces led by Gen. Frederick Funston finally captured General Emilio Aguinaldo in the area on March 23, 1901. Isabela was reorganized as a province under the American regime through Act No. 210, passed August 24, 1901. Its first provincial governor was Rafael Maramag, a former Municipal President (then a term for Municipal Mayor) of the capital town Ilagan. Rafael Maramag was also the first Municipal President of Ilagan City and was succeeded by his brother Gabriel. Isabela was ruled by the Dy family for 34 years, from 1969 to 2004. The dynasty started with the patriarch of the family, Faustino Dy, Sr. who served as the Cauayan Mayor from 1965–1969 and as a Governor of Isabela for 22 years (1969–1992). He was replaced by his son, Benjamin G. Dy in the gubernatorial seat from 1992 to 2001. Another Dy took the gubernatorial seat in 2001 when Faustino Dy Jr. won the 2001 elections after having served first as a Representative of the 2nd district of the province from 1992 to 2001. It was only in the 2004 elections that the Dys' ruling over the gubernatorial seat was taken away from the family when Grace Padaca won.
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. Other ethnic groups followed and Isabela became the “melting pot of the north”.
In 1995, Republic Act Number 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 strong majority voting not to separate the province.
In 2012, the capital town of Ilagan officially became a city, winning 96% of the votes in the plebiscite conducted in August 11, 2012. The night after the voting, COMELEC Commissioner Armando Velasco declared Ilagan as the new component city of the province.