Atero, after the skirmish in the valley of Putaendo, had retreated to Chacabuco, and Marcó hurriedly sent reinforcements, offering the soldiery a reward of twenty dollars for each one of the enemy killed, and twelve for each prisoner; but, at the same time, he secretly sent off his baggage to Valparaiso, and not until the 10th did he appoint a commander for the army assembling at Chacabuco. He then selected Colonel Maroto of the Talavera regiment, who reached the headquarters at the farmhouse on the evening of the 11th. Maroto found under his orders 1,500 infantry, 500 cavalry, and five guns, a force far inferior in numbers to that of the invaders, and depressed in spirit, but they were the flower of the Spanish army. All that he had time to do that evening was to strengthen an outpost which was stationed on the summit in a position which commanded the eastern pass, purposing to occupy the heights with his entire force on the following day.

At two in the morning of the 12th February, under a bright moon, the Argentine army commenced their advance, the infantry leaving their knapsacks behind them. Flanking parties from Soler’s division were the first to meet the enemy, but had barely time to exchange a few shots when the position was attacked by O’Higgins, who drove this advanced guard before him over the summit. The Royalists retreated in good order upon the main body, which had advanced three miles up the valley at dawn of day.

Maroto, believing that the whole force of the Patriots was in pursuit of his vanguard by the main road, withdrew his army across the valley, which was intersected by a muddy stream, and took up a strong position on the opposite slope, placing two of his guns so as to command the mouth of the pass, and extending his line to a hill on his extreme left, where he established a strong force of infantry, with the cavalry in the rear.

Zapiola, with three squadrons of the grenadiers, harassed the retreat of the Royalist vanguard, but could make no impression upon it, the ground being unfavourable for cavalry, but he succeeded in preventing the enemy from occupying two hills at the mouth of the pass, where they might have seriously hindered the advance of O’Higgins; and advanced into the valley till forced to retire by the fire of the two guns in position in front.

At 11 A.M. O’Higgins debouched from the pass, and drew up his infantry in line on the open ground under fire of the enemy. For an hour he contented himself with returning their fire and beating off their skirmishers, till, as he afterwards said himself, his blood was boiling to be at them. In his excitement he forgot the positive orders of San Martin to wait for Soler before attacking the enemy, and gave the word to charge. His men advanced with alacrity, but were soon entangled in the muddy stream, which they in vain attempted to cross under the fire of the enemy, and finally retreated in disorder to the mouth of the pass.

San Martin, sitting on his war-horse, saw from the heights above the repulse of his lieutenant. At once he sent off his aide-de-camp Condarco to hasten the march of Soler. This is the incident in his life which is commemorated in the equestrian statue which now graces the Plaza San Martin in Buenos Ayres.

He then galloped down the slope and joined O’Higgins. As he reached the lower ground, he noticed an extraordinary movement in the ranks of the enemy, and then descried the head of Soler’s column advancing rapidly on his flank.

O’Higgins again advanced, while the grenadiers under Zapiola charged the centre of the enemy, and sabred his artillerymen at their guns. The position was carried by the bayonet, and the Royalist infantry formed square on their centre. Colonel Alvarado, with the vanguard of the right wing, at the same time captured the hill on the left flank of the Royalists, while Necochea and Escalada charged the cavalry in the rear. The victors then fell simultaneously upon the square, which was speedily broken. Some of the fugitives made for the farmhouse in their rear, but found their retreat cut off by Soler, and were forced to surrender at discretion; others tried to escape by the valley, and there fell under the sabres of the grenadiers.

The Royalists lost in this action 500 killed, 600 prisoners, all their artillery, a standard, and two flags; while the loss of the Patriots was 12 killed and 120 wounded. But the moral effects of the victory were still greater; the disaster of Chacabuco spread panic among the adherents of the Royal cause all over Chile. Only three men were undismayed—Barañao, Ordoñez, and Sanchez.

Barañao, on the march with his hussars to join the army, was met at the entrance to the plain of Chacabuco by news of the disaster. He countermarched to Santiago, and offered Marcó to take up an infantry soldier behind each of his horsemen, and to fall upon the Patriot camp by night; but Marcó thought of nothing but his own safety, and fled to Valparaiso, leaving the capital in the hands of the populace.