Complex sentence: For almost seven years they lived in poverty among hostile Native Americans, until the three men managed to reunite with Cabeza de Vaca in September 1534, somewhere west of the Sabine River.
Split into simpler sentences: For almost seven years, they lived in poverty among hostile Native Americans. After that period of time, the three men managed to reunite with Cabeza de Vaca in September 1534, somewhere west of the Sabine River.