Battle of Las Tres Acequias The Battle of Les Tres Acequias , fought during the Chilean War of Independence , occurred near San Bernardo on 26 August in 1814 . The confrontation occurred between the two factions of Carrera and Bernardo O ' Higgins , resulting in a defeat for O ' Higgins that would in turn lead on to the defeat of the nationalists by the royalist forces at the battle of Rancagua a month later . Background . On 23 July 1814 , after two months of arguing with the Supreme Director Francisco de la Lastra , and unable to retreat to Argentina , José Miguel Carrera seized power in Chile once again , dismissing the Director and installing a new junta . Carrera had refused to accept the Treaty of Lircay , signed by Francisco ' s government . The treaty would have overturned many acts of the governments in the last few years , including removing the Chilean flag created during the administration of Carrera , and introducing acts of devotion to King Fernando VII and a promise of absolutist restoration . On a more personal level , the negotiations over the treaty had not included provision for the exchange of prisoners ; Carrera was a prisoner of the royalists in Chillán at the time of the signature of the treaty , before then escaping from royal custody to join other patriots in exile in Mendoza , Argentina . O ' Higgins , meanwhile , was still the commander in chief of Francisco ' s government , and had acquiesced to the signature of the treaty . O ' Higgins marched from Talca towards Santiago with a division of troops to remove Carrera . O ' Higgins regarded Carrera and his political faction as being responsible for the military failures of the earlier campaign , as well as the previous overthrow of O ' Higgins ' political mentor , Juan Martínez de Rozas . In the eve of the battle O ' Higgins encamped in the Mardones property , to the south of Maipo River , waiting for Carrera ' s forces , overnighting at the small hamlet of Pérez farm . The battle . On the morning of 26 August , the then brigadier O ' Higgins crossed the Maipo River and on to the level ground on the other side . His intention was to advance rapidly on Santiago and thereby to defeat Carrera ; because of this , he did not initially realise the size and disposition of Carrera ' s forces . At 13 : 00 hours , O ' Higgins ' advance parties , under the command of Ramon Freire , joined combat with the forward echelons of Carrera ' s forces , under the command of José ' s youngest brother , Colonel Luis Carrera , protected by the a low bank . Luis Carrera had deployed his forces with the infantry to his right , the artillery to the centre , his cavalry to his left and behind these , a line of eight hundred cavalry militia from Aconcagua under the command of the colonel José Maria Portus . These militia were badly equipped , of poor quality , and were only deployed during the final phases of the battle . Eschewing further reconnaissance , O ' Higgins ordered his men forward in a determined attack against the larger enemy force , apparently optimistic following the early preliminary victory delivered by Freire along the bank . After an unfruitful cannonade , O ' Higgins attacked in force at 16 : 00 , placing his infantry in the centre of his line , supported by four guns , and dividing his cavalry between both flanks . After one hour of fruitless attack , and having received numerous losses without causing much damage to the defenders , O ' Higgins ' forces began to retreat in relative disorder . This moment was seized by the cavalry of Luis Carrera , who ordered Diego Jose Benavente to encircle the enemy ' s right flank and begin to further disrupt his line . This was followed by the mounted militia of Aconcagua charging the middle of O ' Higgins ' line , breaking through it and taking numerous prisoners , amongst them four senior officers . O ' Higgins ' men fled , mainly to the south , attempting to cross the Maipo river and seeking safety in the buildings around Chena . O ' Higgins ' own mount had collapsed wounded , and he retreated from the field on a borrowed horse , leading a unit of 100 men to safety . Meanwhile , the bulk of the 3rd division of Carrera ' s force , under the command of José Miguel Carrera himself , had been positioned on the suburbs of Santiago at the beginning the battle . Despite a force march , it did not arrive in time to take part in the main action . When the cavalry from the 3rd division arrived , it joined the units chasing O ' Higgins ' men from the battlefield - but as the sun set around 18 : 30 , Carrera ' s men gave up the pursuit . Consequences of the battle . Luis Carrera did not pursue his enemies any further that night , keeping to his position . He placed some forces as a diversion towards the " Hacienda de Tango " , accompanied by the guns he had seized from O ' Higgins . Whilst these guns provided a desultory bombardment , Carrera ' s main body left Perez ' s farm and retreated two kilometers to the north , to the hamlet of Ochagavia . On the next day , O ' Higgins finally regrouped to the south of the Maipú and reunited his men , with the intention of joining them with his rear units and undertaking a fresh attack . In the midst of this , news came from Talcahuano of the arrival of the royalist expedition of General Mariano Osorio , advancing quickly towards them . This intervention encouraged both sides to settle their differences and to jointly defend their country . O ' Higgins sent a representative to José Miguel Carrera to convey the news of the situation and his intentions . After some further negotiations , the two leaders settled their differences at the " Hacienda de Tango " , jointly signing a declaration in Santiago on 4 September . On the following day O ' Higgins left the capital to assume the leadership of the 1st division , consisting of his old forces , under the overall command of José Miguel Carrera . These forces would conduct the defence of Chile , leading up to the disaster of the battle of Rancagua .