The town's rich religious heritage continues to be a significant part of its identity, with numerous churches and cultural practices rooted in its Catholic origins.

[6] Its naturally shaped coastline offered an excellent harbor for foreign vessels entering Lingayen Gulf, establishing the area as a significant trading hub.

This strategic location attracted Japanese and Chinese merchants who engaged in the exchange of goods with the native population, transforming the settlement into a thriving center of commerce.

[7][8] In June 1572, Spanish voyagers led by conquistador Juan de Salcedo landed in the trading port of Agoo after navigating the Angalacan River in Pangasinan and following three Japanese ships.

[7] In 1661, Andres Malong of Pangasinan led a rebellion against Spanish colonial rule in an attempt to liberate several areas in Northern Luzon, including the present-day province of La Union.

However, his forces suffered a decisive defeat during the Battle of Agoo, where the Spanish, with their superior weaponry and strategic fortifications, repelled the rebellion.

[6] The Spanish authorities had already established the settlements in Santo Tomas as a barrio of Mangaldan, a pueblo under the province of Pangasinan, headed by a gobernadorcillo and a cabeza de barangay.

[7] By the 1700s, due to population pressures and oppressive conditions under Spanish rule, Ilocano migrants from the Ilocos provinces and nearby towns began settling in the coastal areas of La Union.

They settled, cultivated lands for agriculture, and improved the settlement, with intermarriage occurring between the Ilocano settlers and the Pangasinans leading locals to Ilocanized Pangasineses.

Don Lorenzo de los Reyes, a prominent native of Santo Tomas, was appointed its first gobernadorcillo, overseeing local governance under the Spanish administration.

Separation of Conception On August 7, 1869, Governor-General Carlos de la Torre decreed the conversion of Barrio Concepcion in Santo Tomas into a new town called Rosario.

[10] Through the years, the residents of Santo Tomas actively participated in the fight for independence against Spanish colonial rule across La Union.

Under the leadership of General Manuel Tinio y Bondoc, a close ally of the Philippine president Emilio Aguinaldo, the locals engaged in significant resistance efforts in Northern Luzon.

On November 18, 1899, American troops arrived in coastal La Union via Rabon Point after successfully taking Pozorrubio and San Fabian in Pangasinan under General Samuel B.M.

[10][15] By May 1, 1901, the Gen. Manuel Tinio Brigade surrendered to the Americans, marking the end of the Philippine-American War in La Union and the surrounding region.

[10] When World War II broke out in 1941, Japanese soldiers landed along the shores of Santo Tomas on December 1941 three days before Christmas.

Santo Tomas is a coastal municipality located on a narrow plain between the foothills of the Cordillera Central and the Lingayen Gulf (also known as the South China Sea).

Situated in the southern part of the province, Santo Tomas is bordered by Agoo to the north, Tubao and Pugo to the northeast, Rosario to the south and southeast, and the Lingayen Gulf to the west.

The coastal plains transition sharply into steep ranges, with elevated areas to the west and hilly and mountainous terrain rising gradually to the east.

Both bodies of water are renowned fishing grounds for the residents of Santo Tomas, especially for their high-quality milkfish and oysters, which are considered among the best in the region.

Santo Tomas is predominantly Roman Catholic, with significant populations adhering to other Christian denominations, including Iglesia ni Cristo, Protestantism, Aglipayan, Pentecostalism, and Jehovah’s Witnesses.

In addition to dried fish, the town has developed industries such as basketry, native rice cake delicacies, and woodcarving, which serve both local markets and visitors.

The town's natural beauty, including its beaches, fishponds, and Sungyot Island, makes it an attractive place for visitors looking to explore rural life, agricultural practices, and eco-friendly activities.

Eco-tourism initiatives focus on preserving the environment while offering nature-based experiences, such as bird watching, hiking, and fishing tours.

Local cuisine includes Damortis dried fish (daing stalls along the national highway)[clarify], puto, Bibingka, Nilatekan, and Patopat.

The patron saint of the town fishermen is Senora Virgen del Mar Cautiva (Virgin of the Sea), whose Feast Day is celebrated every 26 April) at Poblacion.

[citation needed] One of Santo Tomas' cultural icons is the 1785 Holy Guardian Angels Parish Church, which celebrates the Patronal Fiesta on October 2.

[46][47] In 1845, Padre Santiago Romero, Kura Paroko's[clarification needed] carved three religious statues for the Church out of devotion to the "Virgin of the Rosaries".

"Matutina" through the China Sea is held yearly on July,[clarification needed] where the three images are inserted in three boxes and delivered to Santo Tomas by sailboat.

In Bolinao, Pangasinan, Jolo pirates seized the "Matutina" and threw the three boxes of the statues into the sea, after severing the left forearm of the Virgin Mary.