Tetralogies

thumb|Joseph and His Brothers: A four-part novel by Thomas Mann, written over the course of 16 years A tetralogy (from Greek τετρα- tetra-, "four" and -λογία -logia, "discourse") is a compound work that is made up of four distinct works. The name comes from the Attic theater, in which a tetralogy was a group of three tragedies followed by a satyr play, all by one author, to be played in one sitting at the Dionysia as part of a competition.

congenital heart defect, whose symptoms include episodes of bluish skin color, whose embryology includes anteriosuperior displacement of the infundibular (aorticopulmonary) septum

thumb|King Henry V thumb|King Henry VI