The Augustinian missionaries who preached Catholicism in Pampanga extended their outposts into what is now the province of Nueva Ecija by following the Rio Grande dela Pampanga. Thus, Santol (present day Barangay Santor) was established in 1659. In 1760, Bongabon was named as a town and parish under the patronage of St. Francis of Assisi.

Bongabon was the first capital of Nueva Ecija.