Battle of Medina The Battle of Medina was fought approximately 20 miles south of San Antonio de Bexar ( modern - day Downtown San Antonio in the U . S . state of Texas ) on August 18 , 1813 as part of the Mexican War of Independence against Spanish authority in Mexico . Spanish Royalist troops led by General José Joaquín de Arredondo defeated Republican forces ( calling themselves the " Republican Army of the North " ) , consisting of Tejano - Mexican and Tejano - American revolutionaries participating in the Gutiérrez - Magee Expedition , under General José Álvarez de Toledo y Dubois . Background . Bernardo Gutiérrez de Lara took up the effort to free Texas from Spain . Colonel Gutiérrez visited Washington , DC , and gained support for his efforts . In 1812 , Colonel Augustus William Magee , who had commanded United States Army troops guarding the border of the “ Neutral Ground ” between Louisiana and Texas , resigned his commission and formed the Republican Army of the North to aid the Gutiérrez - Magee Expedition . The army flew a solid emerald green flag , thought to have been introduced by Colonel Magee , who was of Protestant Irish descent . Nacogdoches was taken on August 12 , 1812 , with little opposition , and on November 7 , 1812 the Republican Army of the North marched into what is present day Goliad , where they took the Presidio La Bahia . Spanish royalist s soon confronted them , beginning a four - month siege . While at La Bahia , Colonel Magee died on February 6 , 1813 . After numerous battles and heavy losses , the Spanish lifted the siege and returned to San Antonio de Bexar . On March 25 , 1813 the Republican Army of the North left La Bahia for Bexar after receiving reinforcements . Colonel Samuel Kemper replaced Magee , and Lieutenant Colonel Reuben Ross was elected second in command . Battle . There were approximately 1 , 400 Texian s in Lara ' s Republican Army at the time , composed of Tejanos , Americans , Euro - Mexicans ( Criollos ) , former Spanish Royalist soldiers aided by an auxiliary force of Indians and at least one black slave . This army being led by General Toledo , had camped on the north bank of the Medina River , about six miles north of Arredondo ' s 1 , 800 Royalist troops which were encamped near present - day Leming , Texas . The battle lasted for four hours . Toledo ' s plan called for an ambush on the Royalist troops as they would march through a defile on the Bexar – Laredo road . Similarly , Arredondo had sent out a scouting party with some cavalry in the morning to try to determine the location of Toledo ' s troops . Quite accidentally , they happened upon the Republican ambush and retreated after a brief exchange of fire . The Republican soldiers gave chase , apparently mistaking the cavalry which kicked up large clouds of dust for the main army ; it is believed that Toledo tried in vain to stop his troops from advancing . In their pursuit , they were slowed down by the sandy terrain ; the guns they were dragging with them became deeply mired . By the time they reached the Spanish lines , they were tired and thirsty . However , they did manage to rout some Spanish artillery units and were trying a flanking maneuver when they were repulsed by Spanish cavalry units . The situation had been less than clear for Arredondo , and he was prepared to order his troops to fall back , when he seems to have been informed by a defector that the Republican troops were also attempting to disengage due to exhaustion . He then ordered an advance instead . The Republicans fled in disorder . Toledo and a few of their associates headed straight for Louisiana . Bexarenos stopped in San Antonio just long enough to gather their families . The Spanish army continued to press , killing many of the fleeing soldiers . Most of the remainder were captured and then in a portent of the future Texas War of Independence were summarily executed . Fewer than 100 out of 1 , 400 soldiers on the Republican side survived , while the Royalists lost only 55 men . The remains of the Republican troops were left to rot and not buried until 1822 when José Félix Trespalacios , the first governor of Coahuila y Tejas under the newly established United Mexican States , ordered a detachment of soldiers to gather their bones and bury them honorably under an oak tree that grew on the battlefield . The subsequent punitive measures against the supporters of the revolt had a negative effect upon the province . It is believed that the counter - insurgency policies of the Spaniards led to a substantial decline of the Tejano population . Some of Guttierrez - Magee participants were sons of American revolutionaries or fought with Andrew Jackson in the War of 1812 , and of the few who survived , some fought again during the second Texas Revolution in 1835 – 36 . José Antonio Navarro , a founding father of Texas and José Francisco Ruiz , both future signers of the 1836 Texas Declaration of Independence , took part in the 1812 - 1813 , Magee , Gutiérrez and Toledo resistance movements and later served as leaders in the Texas Revolution . One of the dead , Peter Sides , was not a son of , but an actual veteran of the American Revolution . Sides ( originally Seitz ) was about 62 when he marched off from his home in Baton Rouge , Louisiana with Magee and the other revolutionaries . A native of North Carolina of German ancestry , Seitz was a career soldier who fought in the first militia at Nashborough ( later Nashville ) and in Logan County , Kentucky before he and his family relocated to Baton Rouge in 1799 . Markers from the Daughters of the American Revolution and the Daughters of the Republic of Texas have been placed on the battle site in Sides ’ honor . Nearly all the names of the other 1 , 300 or so dead from the Republic Army of the North have been lost to history . Battlefield markers . The location of the Battle of Medina has not been archaeologically determined . There are three historical markers for the battle . The first marker was placed by the State of Texas for the 1936 Texas Centennial at the southeast corner of U . S . Route 281 and Farm to Market Road 2537 in Bexar County . The second marker was placed by the State of Texas in 2005 at the corner of Old Applewhite Road and Bruce Road in Atascosa County . The third marker was placed by Robert P . Marshall in 2013 on Old Pleasanton Road south of the intersection with Bruce Road . This marker is based on his own research and not recognized by the state .