This dissertation is a study of the Eastern Apache nations and their struggle to survive with their culture intact against numerous enemies intent on destroying them. It is a synthesis of published secondary and primary materials, supported with archival materials, primarily from the Béxar Archives. The Apaches living on the plains have suffered from a lack of a good comprehensive study, even though they played an important role in hindering Spanish expansion in the American Southwest. When the Spanish first encountered the Apaches they were living peacefully on the plains, although they occasionally raided nearby tribes. When the Spanish began settling in the Southwest they changed the dynamics of the region by introducing horses. The Apaches quickly adopted the animals into their culture and used them to dominate their neighbors. Apache power declined in the eighteenth century when their Caddoan enemies acquired guns from the French, and the powerful Comanches gained access to horses and began invading northern Apache territory. Surrounded by enemies, the Apaches increasingly turned to the Spanish for aid and protection rather than trade. The Spanish-Apache peace was fraught with problems. The Spaniards tended to lump all Apaches into one group even though, in reality, each band operated independently. Thus, when one Apache band raided a Spanish outpost, the Spanish considered the peace broken. On the other hand, since Apaches considered each Spanish settlement a distinct "band" they saw nothing wrong in making peace at one Spanish location while continuing to raid another. Eventually the Spanish encouraged other Indians tribes to launch a campaign of unrelenting war against the Apaches. Despite devastating attacks from their enemies, the Apaches were able to survive. When the Mexican Revolution removed the Spanish from the area, the Apaches remained and still occupied portions of the plains as late as the 1870s. Despite the pressures brought to bear upon them the Apaches prevailed, retaining their freedoms longer than almost any other tribe.