Bolivar rejoined the army in March, and soon after conducted his forces to join the patriots in New Granada. Two battles, on the 1st and 23d of July, were fought to the advantage of the patriots, whose cause obtained a final triumph in the decisive victory won August 7, at Bojaca. Bolivar advanced at once to Bogotá, where he was enthusiastically welcomed; and within a short time, eleven provinces of New Granada announced their adhesion to the cause of independence. He summoned a congress, by which he was appointed President, and Captain-general of the Republic. Meanwhile a party, jealous of his intentions, had obtained the ascendancy in the Venezuela Congress held at Angostura; and Bolivar, fearful of being supplanted, quitted the scene of war with his best troops and marched to Angostura. His presence, with such a force, turned the scale in favour of the party attached to his interest. It was determined to summon a general convention from the independent provinces of Venezuela and Granada; and December 17, 1819, the celebrated decree was passed by which the two states were united, and entitled the Republic of Columbia. Bolivar was appointed President.
Strengthened by union, the patriots took the field in greater force than they had hitherto been able to raise. The course of war during 1820 was on the whole favourable to them. In November, an armistice for six months was concluded. Soon after the renewal of hostilities, an important victory was gained by the Columbian troops under Bolivar, at Carabobo, not far from the city of Valencia, June 21, 1821, which may be regarded as having closed the war in Venezuela. Before the end of the year, Columbia was nearly cleared of Spanish troops, with the exception of the province of Quito; and time was found to attend to the establishment of civil order. The constitution of the short-lived Columbian Republic was adopted, August 20, 1821, and Bolivar was appointed First Constitutional President.
The war was then directed against the Spaniards in the south. In January, 1822, Bolivar himself conducted operations in the province of Pasto, lying to the north of Quito, while General Sucre, who had been sent previously to assist the cause of independence in Guayaquil, after liberating the southern provinces of Loxa and Cuenca, advanced northwards, and secured independence to the province of Quito by the decisive victory of Pichincha, May 24, 1822. But though this portion of Columbia was now cleared of enemies, there could be no security to the frontier provinces while the Spaniards held Peru; and it was therefore determined to send assistance to the patriots in that country. Bolivar landed at Lima, September 1, 1823, and was invested with supreme power as Dictator of Peru. It was not until the end of 1825, however, that the war of independence was finished; and the honour of this, in a military point of view, belongs rather to Sucre than to Bolivar.