Realm is a land ruled by a king or queen. Milton uses this definition to compare Hell to Egypt, under the rule of the impious Pharaoh that Moses punished with a number of plagues cast upon the land of Egypt. Milton compares the reign of the Pharaoh to Satan's rule over Hell. Milton compares Moses casting a plague of locust on Egypt to Satan, in order to describe the control Satan had over the fallen angels. Milton uses the story of the Exodus to introduce the character of the evil Pharaoh in order to foreshadow Satan's character. The word realm compares Satan and the impious Pharaoh.