In the 16th century, northern Mexico was torn by strife as Indian inhabitants resisted Spanish efforts to enslave them. A century later, the wealthy humanitarian Antonio Balcarcel sought justice and support for missionaries trying to Christianize the region. In the spring of 1675, he sent an armed expedition under Fernando Del Bosque to accompany Fray Juan de Larios on a mission north of the Rio Grande, joined also by the army chaplain Fray Dionisio de San Buenaventura. Entering Texas near present Eagle Pass, the party marched almost to the present site of San Antonio. Three days after entering Texas, while camped on the Nueces about nine miles southwest of present Uvalde, they set up a portable altar and gathered with some 1,172 Indians to hear Fray Larios chant the Mass. Later, Fray Larios baptized 55 infants and instructed the adult Indians for possible future baptism. The celebration on the Nueces on May 16, 1675, became known as the earliest recorded occasion of a High sung Mass in Texas, and the missionary activity that began that day eventually led to the founding of the Texas mission system.