The process in which the anatomical structures of the diencephalon are generated and organized. The diencephalon is the paired caudal parts of the prosencephalon from which the thalamus, hypothalamus, epithalamus and subthalamus are derived; these regions regulate autonomic, visceral and endocrine function, and process information directed to the cerebral cortex. [ GOC:dgh GOC:cls http://openisbn.com/search.php?q=0838580343&isbn=1/ GOC:jid GOC:dph ]