The Battle of Calderon Bridge was a major battle of the Mexican War of Independence which occurred on 17 January 1811. Following Father Miguel Hidalgo y Costilla's failed attempt to take Mexico City in 1811, the Mexican insurgent army retreated towards Guanajuato, pursued by Felix Maria Calleja del Rey's Royalist army. The insurgents were unable to defend Aculco, forcing them to continue their retreat to Guadalajara. The insurgent army took up a defensive position at the Calderon Bridge, which carried the road from Guanajuato to Guadalajara, and, on 17 January 1811, the 8,000-strong Royalist army met the insurgents in battle. The professional Spanish soldiers defeated the undisciplined and poorly-equipped remnants of the rebel militia, and the explosion of an insurgent munitions wagon dispersed much of the insurgent force and contributed to a rout. Not long afterwards, many of its leaders - the old, charismatic priest among them - were captured and executed.