On September 16, 1807, he witnessed the Basi Revolt in Ilocos, which culminated twelve days later when the Spanish successfully quelled the rebels.

Fernández de Folgueras left a detailed report of the events that occurred during the incursion of the South American forces.

[2] Folgueras, also, created the province of Ilocos Norte on February 2, 1818, and reestablished the Sociedad Económica de los Amigos del País on December 17, 1819.

On October 30, 1822, Fernández de Folgueras gave the office to Juan Antonio Martínez and returned to become the lieutenant governor once again.

On 1823, creoles and mestizos staged an insurrection against the government of Martínez because of the growing sentiments on how the Spanish authorities treated them.