Pampanga is about 850 square miles in area and is presently inhabited by more than 1.7 million people. During the Spanish times, Pampanga was one of the richest Philippine provinces.

It is believed that early Pampangans were descendants of Malayan pioneers from the Malay Peninsula and Singarak Lake in West Sumatra. They settled along the river banks of the Rio Grande de la Pampanga in the Island of Luzon covering a large territory which extended to the Gulf of Lingayen in the North, to the Zambales mountains in the West, to the Sierra Madre range in the East and to Manila Bay in the South.

The name Pampanga was attributed to the early settlers along the Pampanga River who were then called "taga pangpang". The Spaniards have a difficulty pronouncing the "ng" part which led to the corruption of the original word to the present term Pampanga.

Ancient Pampanga's territorial area used to include portions of the provinces of Bataan, Bulacan, Nueva Ecija, Pangasinan, Tarlac and Zambales in the big Island of Luzon of the Philippine Archipelago. The province derived its name from the Kapampangan words "Pangpang ilog" meaning "riverside" where the early Malayan settlements were concentrated along the Rio Grande de la Pampanga (Great Pampanga River) until such time the adventurous Malayan settlers expanded their domain into the hinterlands of the Kapampangan region.

Pampanga was the first province in the island of Luzon inaugurated by the Spaniards. It was founded on December 11, 1571 in the same year the City of Manila was established by Spanish Governor Miguel Lopez de Legaspi as the seat of national government. For governmental control and taxation purposes, the Spanish authorities subdivided the province into towns (pueblos) which were further subdivided into districts (barrios) and in some cases into royal and private estates.

Due to excessive abuses committed by some grantees of private estates, the King of Spain prohibited in 1574 the awarding of private estates (encomiendas). However, the royal decree was not fully enforced until the year 1620. In a report of Philippine encomiendas on June 20, 1591, Spanish Governor Gomez Perez Dasmarinas reported to the King of Spain that La Pampanga’s encomiendas were Batan, Bitis y Lubao, Macabebe, Candava, Apali, Calompit, Malolos, Binto, Guiguinto, Caluya, Bulacan and Mecabayan. The encomiendas of La Pampanga at that time had eighteen thousand six hundred and eighty whole tributes, or seventy-four thousand seven hundred and twenty souls.

Pampanga is now about 850 square miles (2,181 square kilometers) in land area and inhabited by about 1,636,000 people (per the 1995 Philippine National Census). As other Luzon provinces were created due to increases in population, some well-established Pampanga towns were lost to new emerging provinces in Central Luzon.

The historic province of Bataan which was founded in 1754 under the administration of Spanish Governor General Pedro Manuel Arandia, absorbed from the province of Pampanga the municipalities of Abucay, Balanga, Dinalupihan, Llana Hermosa, Orani, Orion, Pilar, and Samal.

The old Pampanga towns of Aliaga, Cabiao, Gapan, San Antonio and San Isidro were ceded to the province of Nueva Ecija in 1848 during the term of Spanish Governor-General Narciso Claveria y Zaldua. Claveria was best remembered for issuing memorable decrees during his incumbency. One of Claveria's history-making decrees was issued on August 16, 1844, which ordered that Tuesday, December 31, 1844 should be officially considered as Wednesday, January 1, 1845 thus eliminating December 31, 1844 from the Philippine calendar. There were no births nor deaths officially registered in the Philippines on that date.

On November 11, 1849, Claveria issued a decree to systematize the selection and registration of names of the Filipino people. The decree called for Filipinos to have first names and surnames. It should be recalled that the early Filipinos usually have only one name like Lakandula, Soliman, Lapulapu, Humabon. The decree included a list of Spanish surnames which were adopted by some Filipinos while others opted for Filipino last names instead. Today, many Filipinos have Spanish family names like Arnedo, Bonifacio, David, Escaler, Fausto, Gonzalez, Gutierrez, Hernandez, Ibarra, Inventor, Joven, Lopez, Lorenzo, Marquez, Mercado, Navarro, Pineda, Regala, Reyes, Rodriguez, Ronquillo, Ventura, Simon, Torres, Vargas, Vergara, Zuniga, etc.

The municipality of San Miguel de Mayumo of Pampanga was yielded to the province of Bulacan in the same provincial boundary configuration in 1848.

In 1860, the northern towns of Bamban, Capas, Concepcion, Victoria, Tarlac, Mabalacat, Magalang, Porac and Floridablanca were separated from Pampanga and were placed under the jurisdiction of a military command called Comandancia Militar de Tarlac. However, in 1873, the four latter towns were returned to Pampanga and the other five towns became municipalities of the newly created Province of Tarlac.