Filipino revolutionaries laid siege to a fortified church defended by Spanish troops in the town of Baler, Aurora, for 337 days, from 1 July 1898 until 2 June 1899.

In September 1897, the Spanish garrisoned Baler with 50 Civil Guard soldiers under Lieutenant José Mota, to prevent Emilio Aguinaldo from receiving smuggled arms.

By 1898, with the resumption of the Philippine Revolution, Baler was still reachable only by ship or by traversing on foot through nearly impassable jungle trails across the Sierra Madre mountain range that were often washed out by torrential tropical rains.

[6] On 1 June 1898, las Morenas ordered his men to begin digging a well, stocking food supplies and ammunition, and fortifying the church compound of San Luís de Tolosa in Baler's town square against a possible attack.

Then on the night of 30 June, 800 Filipino troops under Teodorico Novicio Luna attacked, and the garrison fell back to the church.

At the start of the siege, the Spanish had provisions of flour, rice, beans, chickpeas, bacon, canned Australian beef, sardines, wine, sugar, and coffee – but no salt.

[19] By mid-November, having failed to dislodge the Spanish defenders, Villacorta, under a flag of truce, left newspapers on the church steps that told of Spain's planned departure from the Philippines and that the Spanish–American War was over.

Villacorta brought in Spanish civilians and ultimately a military officer left behind to wrap up Spain's affairs on the island, to no avail.

[21] The Treaty of Paris formally ending their war with Spain having been signed in December, and after a specific request from the Archbishop of Manila on March 23, the Americans intervened in April.

[25][26] When their food ran out on 24 April, the Spanish resorted to eating stray dogs, cats, reptiles, snails and crows.

[27] On 8 May, Filipino artillery shelling hit an improvised cell that held three Spaniards who had attempted to desert earlier in the siege.

This was a blow to the Spanish as the deserter had important intelligence to share about their dire straits, and helped fire the cannon on the church to good effect.

[10][34] Martín Cerezo later published a memoir, El Sitio de Baler, where he gave his reasons for holding out: "It would be somewhat difficult for me to explain, principally, I believe through mistrust and obstinacy.

[39] Las Morenas was posthumously promoted to "comandante" (major) and awarded the Laureate Cross of Saint Ferdinand, Spain's highest military medal.

[10] The feat of the Spanish so inspired the United States Army General Frederick Funston that he had Martín Cerezo's memoir translated and gave copies to all his officers.

Section 1 of the Act stated that "June 30 is a day when President Emilio Aguinaldo commended the besieged Spanish soldiers in the Church of Baler for their loyalty and gallantry.

Chief of Staff of the Spanish Prime Minister, Miguel Utray Delgado led the celebration of the 22nd Philippine-Spanish Friendship Day and the Siege in Baler's 126th anniversary.