Complex sentence: The cadet branch (brother of Cosimo the Elder) derives from Lorenzo the Elder which includes all the Grand Dukes of Tuscany, the Bourbon Kings of France and several Kings of England and Spain, continues to this day.
Split into simpler sentences: The cadet branch derives from Lorenzo the Elder (the brother of Cosimo the Elder). This'cadet' branch includes all the Grand Dukes of Tuscany, the Bourbon Kings of France and several Kings of England and Spain, and continues to this day.