Complex sentence: Upon the death of Gaston of Orléans, the appanage of Orléans reverted back to the crown and was given to Philippe de France, the brother of Louis XIV of France.
Split into simpler sentences: Upon the death of Gaston of Orléans, the Appanage of the Duchy of Orléans reverted back to the crown. The appanage was given to Philippe, the brother of Louis XIV of France.