Pluto
Webster's Dictionary [1]
(n.) The son of Saturn and Rhea, brother of Jupiter and Neptune; the dark and gloomy god of the Lower World.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]
( Πλούτων , Rich), originally only a surname of Hades, as the giver or possessor of riches, is, in the mythology of Greece, the third son of Kronos and Rhea, and the brother of Zeus and Poseidon. On the tripartite division of the universe, he obtained the sovereignty of the under-world-the realm of darkness and ghostly shades, where he sits enthroned as a "subterranean Zeus" — to use the expression of Homer, and rules the spirits of the dead. His dwelling-place, however, is not far from the surface of the earth. Pluto is inexorable in disposition, not to be moved either by prayers or flatteries. He is borne on a car, drawn by four black steeds, whom he guides with golden reins. His helmet makes him invisible, whence, according to some scholars, his name of Hades; although others, with at least equal probability, translate the word the "all-receiver." In Homer, Hades never means a place, but always a person. Moreover, it is to be noticed that the poet does not, divide the realm of the shades into two separate regions. All the souls of the dead — good and bad alike mingle together. Subsequently, however, when the ethical conception of future retribution became more widely developed, the kingdom of the dead was divided into Elysium (q.v.), the abode of the good, and Tartarus (q.v.), the place of the wicked. This change also exercised an important influence on the conception of Pluto. The ruler of the under-world not only acquired additional power and majesty, but the very idea of his character was essentially modified. He was now regarded as a beneficent deity, who held the keys of the earth in his hand, and possessed its metallic treasures (whence his new name Pluto or Plutus), and who blessed the year with fruits, for out of the darkness underground come all the riches and swelling fullness of the soil. Hence, in later times, mortals prayed to him before proceeding to dig for the wealth hidden in the bowels of the earth.
Pluto married Persephone (Proserpina), the daughter of Demeter (Ceres), after carrying her off from the plains of Enna. He assisted his brothers — according to the mythological story — in their war against the Titans, and received from the Cyclops, as a reward for delivering them from Tartarus, the helmet that makes him invisible, which he lent to Hermes (Mercury) in the aforesaid war, to Perseus in his combat with the Gorgons, and which ultimately came to Meriones. The Erinyes and Charon obey his behests. He sits in judgment on every open and secret act, and is assisted by three subordinate judges, Eacus, Minos, and Rhadamanthus. The worship of Pluto was widely spread both among the Greeks and Romans. Temples were erected to his honor at Athens, Elis, and Olympia. Among trees and flowers, the cypress, boxwood, narcissus, and maidenhair were sacred to him; bulls and goats were also sacrificed to him amid the shadows of night, and his priests had their brows garlanded with cypress wreaths. In works of art he resembles his brothers Zeus and Poseidon; only his hair hangs down somewhat wildly and fiercely over his brow, and his appearance, though majestic, as becomes so mighty a god, has something gloomy and terrible about it. There can be little doubt that he, as well as Pan (q.v.), helped to trick out the conception of the devil prevalent during the Middle Ages, and not yet extinct. If it was from Pan that the devil derived those physical characteristics alluded to in the famous "Address to the Devil" by the poet Burns:
"O thou, whatever title suit thee, Auld Hornie, Satan, Nick, or Clootie,"
it is no less certain that it is to Pluto that he owes his position as "king of Hell," "his Blackness," and many of the insignia of his infernal royalty.
The Nuttall Encyclopedia [3]
God of the nether world, son of Kronos and Rhea, brother of Zeus and Poseidon, and husband of Persephone; on the dethronement of Kronos the universe was divided among themselves by the three brothers, Zeus assuming the dominion of the upper world and Poseidon that of the ocean, leaving the nether kingdom to him, a domain over which and forth of which he ruled with a greater and more undisputed authority than the other two over heaven, earth, and sea.