Its foundation as a town is attributed to Juan Martinez de Santo Domingo, a former missionary of Pangasinan who died in Japan on March 19, 1618.Mangaldan started as a "visita" of Calasiao and it remained as such until the Dominicans created it as an independent vicariate under the patronage of Saint Thomas Aquinas on June 2, 1600.This was due to the famous irrigation system which the missionaries built within the confines of the town[6] causing its fertile fields to yield bountiful harvest of palay.The popular carabeef tapa (Filipino-style dried meat), locally known as Pindang is the One Town One Product (OTOP) of this municipality.[21] One of the major sources of revenues here are the thriving market place and the laboratories of renowned pharmaceutical companies that buttressed the coffer of this town.