God of Sleep is a term used to refer to three different figures in Greek mythology. Somnus, the Roman god of sleep, was the son of Nox, the goddess of night. Morpheus, the god of dreams, was the son of Hypnos, the god of sleep. Lastly, Hypnos was the son of Nyx, the goddess of night. All three gods were associated with sleep and dreaming, and were believed to be able to control the dreams of mortals.