The Presidio Nuestra Señora de Loreto de la Bahía, known more commonly as Presidio La Bahia, or simply La Bahia is a fort constructed by the Spanish Army that became the nucleus of the modern-day city of Goliad, Texas, United States. Originally founded in 1721 on the ruins of the failed French Fort Saint Louis, the presidio was moved to a location on the Guadalupe River in 1726. In 1747, the presidio and its mission were moved to their current location on the San Antonio River. By 1771, the presidio had been rebuilt in stone and had become "the only Spanish fortress for the entire Gulf Coast from the mouth of the Rio Grande to the Mississippi River". The civilian settlement, later named Goliad, sprang up around the presidio in the late 18th century; the area was one of the three most important in Spanish Texas.
The presidio was captured by insurgents twice during the Mexican War of Independence, by the Republican Army of the North in 1813 and by the Long Expedition in 1821. Each time the insurgents were later defeated by Spanish troops. By the end of 1821, Texas became part of the newly formed United Mexican States. La Bahía was one of the two major garrisons in Mexican Texas and lay halfway between San Antonio de Béxar (the political center of Spanish Texas) and Copano, the then major port in Texas. In October 1835, days after the beginning of the Texas Revolution, a group of Texianinsurgents marched on La Bahía. After a 30-minute battle, the Mexican garrison surrendered and the Texians gained control of the presidio, which they soon renamed Fort Defiance.