Malolos in the context of Republic of Biak-na-Bato

Bulacan, officially the Province of Bulacan (Tagalog: Lalawigan ng Bulacan; Kapampangan: Lalawigan ning Bulacan; Southern Alta: Lalawigan na Bulacan; Spanish: Provincia de Bulacán), is a province in the Philippines located in the Central Luzon region. Its capital is the city of Malolos. Bulacan was established on August 15, 1578, and part of the Metro Luzon Urban Beltway Super Region. This province is a part of the Greater Manila Area.

It has 572 barangays in 20 municipalities and four component cities (Baliwag, Malolos the provincial capital, Meycauayan, and San Jose del Monte the largest city). Bulacan is located immediately north of Metro Manila. Bordering Bulacan are the provinces of Pampanga to the west, Nueva Ecija to the north, Aurora and Quezon to the east, and Metro Manila and Rizal to the south. Bulacan also lies on the north-eastern shore of Manila Bay.

The Philippine Republic (Spanish: República Filipina), retroactively known as the First Philippine Republic or the Malolos Republic, was a state established in Malolos, Bulacan, during the Philippine Revolution against the Spanish Empire (1896–1898) through the promulgation of the Malolos Constitution on January 23, 1899, succeeding the Revolutionary Government of the Philippines. Emilio Aguinaldo was its inaugural president. It was not recognized by any foreign power, but remained a de facto government.Following the American victory at the Battle of Manila Bay, Aguinaldo returned to the Philippines, issued the Philippine Declaration of Independence on June 12, 1898, and proclaimed successive revolutionary Philippine governments on June 18 and 23 of that year, under which regimes the liberation of Philippine territory from Spain was conducted.

In December 1898, Spain and the United States signed the 1898 Treaty of Paris, ending the Spanish–American war. As part of the treaty, Spain ceded its claim to the Philippines to the United States. The treaty was not considered as in effect until April 11, 1899, when mutual ratifications were exchanged. The Revolutionary Government considered the treaty invalid, and in the meantime had been drafting a republican constitution to succeed its current regime. On on January 21, 1899, the Malolos Constitution was promulgated, and the Republic was inaugurated on January 23. On February 4, fighting had erupted in Manila between American and Filipino forces in what developed into the Philippine–American War. Aguinaldo was captured by the American forces on March 23, 1901, in Palanan, Isabela, and he declared allegiance to the U.S. on April 19, 1901, effectively ending the Philippine Republic.