General Antonio López de Santa Anna (1794-1876) was a Mexican president and general who capitalized on the upheavals of post-independence Mexico by siding with whatever the dominant faction happened to be at any given time. He led the revolution against Mexico's Emperor Agustín I in 1823, aided Vicente Guerrero before revolting against him, and then helped Anastasio Bustamante to power, only to turn against him. Santa Anna was elected to the presidency of Mexico once (in 1833, followed by his own establishment of reactionary dictatorship in 1834) and held a military dictatorship three other times (1841-44, 1846-47, and 1853-55).
Santa Anna appeared at the center of several pivotal nineteenth-century events involving Texas and American plans for western expansion. In 1836, he went to Texas to crush the rebellious U.S. settlers there, and quickly gained infamy in the states for his bloody victory at the Alamo and the massacre he ordered at Goliad. Later that same year, at San Jacinto, Texan Sam Houston defeated Santa Anna's forces and captured the general, forcing him to sign a peace treaty granting Texas its independence. In 1843, Santa Anna threatened war with the U.S. if Texas was annexed into the Union. When war did break out in 1846, the then-exiled Santa Anna returned to Mexico and took command of a Mexican army. At Buena Vista, however, Jefferson Davis's reserve forces stalled Santa Anna's Mexican soldiers. Gen. Zachary Taylor counterattacked, and the Mexicans suffered terrible casualties. Santa Anna's men were then was routed by U.S. forces under General Winfield Scott when they invaded the capital city in September 1847. This invasion created chaos in Mexico, and Santa Anna resigned as president, leaving the government teetering on collapse.