On April 5, 1572 Legazpi merges the encomiendas of Malolos and Calumpit into a single entity to form a new town of Calumpit with Juan Moron and Herrera as co-encomenderos, the Christianization of natives in the old Calumpit was supervised first by Fray Diego de Herrera (one of the first of 5 Augustinian arrived in the islands in 1565) but Herrera dispatched to Mexico and replaced by the new Prior Provincial Fray Martin de Rada as the priest in charge in Calumpit together with Fray Diego Ordoñez de Vivar (a native of Nueva Galicia) as his parochial vicar to the settlements of Hagonoy, Bulakan and Malolos.
The city is 45 kilometres (28 mi) north of Manila, the capital city of the Philippines.
It is one of the major suburbs conurbated to Metro Manila, situated in the southwestern part of Bulacan, in the Central Luzon Region (Region 3) in the island of Luzon and part of the Metro Luzon Urban Beltway Super Region.
After nine years, during the term of Governor-General Don Gonzalo Ronquillo de Peñalosa (1580-1583) the Town of Malolos was officially established as a Town and included it on Bulacan Province and dismembered on Alcaldia de Calumpit on June 11, 1580 and accepted as priory with Fray Matheo de Mendoza as its first minister in an Augustinian Council held in Tondo Convent but the civil administration still belongs to its encomendero at that time, Don Jeronimo Tirado.
From the very beginning, Tagalog made up the majority of the Malolos populace although it was said that Malolos has its Capampangan origin, they were led by prominent ancient families, among them are descendants of the royal native pre-colonial clans of Gatbontons, Gatmaitan, Gatsalian (Gatchalians), Dimagibas, Lakandolas, Ladia and Lacancales and in the 17th century Sangleys families probably came from China then to Tondo and Binondo such as Chichioco, Cojuangco, Chiong, Chico, Cunanan, Tantocos, Tanchangco, Tanjosoy, Tengco, Tenjeco, Lomotan, Manahan, joined by Spanish clans of Adriano, Bautista, Jacinto, Reyes, Santos, Rustia, de Leon, Agustin, Vasquez, Valenzuela, Crisostomo and Estrella.
Searching for inhabited places along the Calumpit river, these Conquistador came upon some natives of a riverside barrio (now Kanalate or Canalate), they asked for the name of the place.