Bolivar went to Cartagena in Colombia and offered his sword to the patriot junta which ruled that city. Given a small military command on the Magdalena River, he embodied a few militia and surprised two posts which were obstructing the navigation of the river. Delighted at these successes, the Cartagena junta sent him reinforcements, with which he captured Ocana, an important city lying east of the Magdalena and not far from Pamplona and the Venezuelan border. The loyalists had collected a considerable force in the Venezuelan province of Barinas, with which they proposed to advance into Pamplona. The patriot chief of this Colombian province appealed to Bolivar and this suggested to him the Napoleonic plan of relieving Pamplona and reconquering Venezuela. On his own responsibility he dashed with only four hundred men over the Andes in front of Ocana, descended into the plain north of Lake Maracaibo, took the royalists on their march to Pamplona by surprise, and routed them. Joined by the patriots from Pamplona, he received formal authorisation to drive the Spaniards from the Venezuelan provinces of Merida and Trujillo. His movements among the mountain valleys were like lightning flashes, and though the Spanish forces were more numerous their commanders were demoralised by his attacks made in defiance of all the rules of prudent warfare. Within fifty days there was not an enemy left in the two provinces, and Bolivar's army had been trebled by enlistments. The New Granadan government ordered him to pause, but he paid no heed. Issuing a proclamation that no quarter would be given, he crossed the mountains south-west into the province of Barinas, annihilated the Spanish forces there, and rushing to the east caught another army of a thousand men near Valencia and destroyed it. Monteverde had no time to concentrate his scattered forces, and the news of this last defeat caused him to flee to the protection of the fortifications of Puerto Cabello. Bolivar occupied Valencia and Caracas without resistance. In a campaign of ninety days, with a handful of New Granadans and mountaineers from western Venezuela, he had defeated and dispersed over four thousand royalists, and conquered the country from the Andes to the capital.