ILAGAN (Bolo) was founded as a Catholic Dominican Mission on April 21, 1619 under the advocacy of Saint Michael the Archangel. The first Vicar was Rev. Fr. PEDRO DE SANTO TOMAS, OP.
ILAGAN was destroyed by a rebellion in 1621.
Ilagan was re-established and was officially founded by REV. FR. PEDRO JIMENEZ, OP., and was officially accepted as an Ecclesiastical Mission by the Dominican Provincial Chapter on May 04, 1686 under the Patronage of Saint King FERDINAND of Castille and León.
The town was then called by its native Gaddang settlers as “Bolo” during the pre-Spanish conquest era. It is one of the populous settlements during that period and site of the vast tobacco plantation in the region making it one of the most important economic areas in Northern Luzon. Shortly after Juan de Salcedo conquered Northern Luzon in 1587, Gov. Rodrigo de Peñalosa sent Capt. Pablo de Carreón to explore Cagayan Valley as well as to establish missions in towns. Among the Spanish missionaries who penetrated deeply into the region was Padre Pedro Jimenez, OP who founded Ilagan.
The town of “Bolo” was situated in the western side of Rio Grande de Cagayan in what is known today as Barangay Naguilian-Baculod. The cultural shock brought by the dominating social and economic regulations introduced by the Spanish authorities propelled the natives to dissent in the Mallig and Ilagan-Tumauini territories in what was known as the Gaddang Revolution. The natives abandoned their settlement after burning their church and houses until 1622 when the Spanish government pardoned and exempted them from paying tribute within three years. After the Gaddang revolt, the natives re-established their settlement upon the efforts of Padre Pedro Jimenez, OP in 1678 on the east side of the river what is known today as Barangay Bagumbayan, thereby giving the legendary name for Ilagan which is the reverse of the word Nagali meaning “transfer”.
The Dominicans accepted the settlement as an ecclesiastical mission given the name San Fernando de Ilagan in honor of its patron, Saint Ferdinand of Castile.
On May 4, 1686, Fr. Pedro Jimenez, OP re-established and founded ILAGAN. It was made the Capital of the entire Cagayan Valley when Brig. Manuel Sanchez Mira was then the Governor of the whole territory. By Virtue of a Royal Decree, the Province of Isabela was created on May 1, 1856, separating from the Provinces of Cagayan and Nueva Vizcaya, and Ilagan became the capital of the Province.
Fr. Pedro V. Salgado, OP
Cagayan Valley and Eastern Cordillera, 1581-1898