Complex sentence: Their son, Orestes in turn, sought vengeance for the death of his father by killing his mother, and was pursued around the world by The Furies, who avenged mothers killed by sons.
Split into simpler sentences: Their son, Orestes, in turn sought vengeance for the death of his father by killing his mother. He was then pursued around the world by The Furies, who avenged mothers killed by sons.