In 1767, Viceroy Marqués de Croix ordered a major military offensive, the Sonora Expedition, to subdue the Seri and Pima tribes. After doing so, the Spanish colonials built an adobe fort with four towers in Guaymas, initially under the command of Captain Lorenzo Cancio. No traces of the fort remain today, but the San José mission is marked by a church located on the road leading to Empalme. Around the same time, the colonists formally mapped the Guaymas Bay and officially founded the city of Guaymas in 1769 by José Gálvez in Real de Alamos on behalf of the viceregal government. Despite the decree, no colonists settled there until the early 19th century.