Complex sentence: Stimulated by this success, Father Gonzalez and two companions journeyed to Uruguay and established two or three small missions in 1627, with good promise for the future until the local tribes killed the priests and the neophytes and burned the missions.
Split into simpler sentences: Stimulated by this success, Father Gonzalez and two companions journeyed to Uruguay and established two or three small missions in 1627. The local tribes killed the priests and the neophytes and burned the missions.