Prior to 1856, there were only two provinces in the Cagayan Valley Region: 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 southward to Aritao comprised the Province of Nueva Vizcaya. In order to facilitate the work of the missionaries in the evangelization of the Cagayan Valley, a royal decree was issued on May 1, 1856 that created the Province of Isabela consisting of the towns of Gamu, Angadanan, Bindang (now Roxas) and Camarag (now Echague), Carig (now Santiago City) and Palanan. The new province was named in honor of Queen Isabela II of Spain.