Complex sentence: As a punishment from the gods for his trickery, King Sisyphus was made to roll a huge boulder up a steep hill, but before he could reach the top of the hill, the rock would always roll back down, forcing him to begin again.
Split into simpler sentences: As a punishment from the gods for his trickery King Sisyphus was made to roll a huge boulder up a steep hill. Before he could reach the top, however, the massive stone would always roll back down, forcing him to begin again.