Martín Perfecto de Cos was a Mexican general and a key figure during the early stages of the Texas Revolution. Born in 1800, he was the brother-in-law of Antonio López de Santa Anna, the President of Mexico. Cos played a significant role in the Mexican military efforts to suppress the rebellion in Texas, leading troops against Texian forces. In 1835, Cos commanded Mexican troops during the Siege of Bexar, where he ultimately surrendered to the Texian army. His defeat marked a turning point in the revolution, as it encouraged further resistance against Mexican rule. After the war, he returned to Mexico, where he continued his military career.