The Republicans had won the Battle of Carabobo on 28 May and had become overconfident when they decided to confront the irregular Royalist army, made up mainly of llanero horsemen, commanded by José Tomás Boves.

The two armies met at the gorges of La Puerta, near the Sémen River and San Juan de Los Morros, in the current state of Guárico.

[2] On 18 June, Bolívar and Mariño arrived in Caracas with 400 survivors, closely pursued by the Royalist vanguard of Captain Ramón González (1,500 cavalry).

On 25 June, José Félix Ribas and 400 cavalry managed to stop González's division and delay its advance to the capital.

It was obvious that it was impossible to defend the capital and on 6 July, Bolívar evacuated Caracas and two thirds of the population, in a long march that is known as the Emigration to East.