Arawn was a master hunter, warrior, and the God of the Dead in Celtic mythology. The origin of his name is of some debate. Among those that study myths, some credit his name as having been derived from Aaron the brother of Moses (biblical), while others seem to think it originates from “The Chronicles of Prydain” written by Lloyd Alexander, in which, Arawn is the unseen villain/s. There are also theories that the origin of the name might be derived from earliest Celtic forms of ar-yo or aratro (to plough or plough), and arawen (grain or cereal).
Annwn, Arawn’s kingdom, was of the other-world and accepted to be a paradise. It was a place where the dead were taken to rejoice in peace and a plentiful supply of all that they could desire. Arawn traveled astride a pale horse led by hunting hounds that were feared by people as their appearance generally meant death. The hounds were said to have red ears and helped to capture souls for Arawn by chasing them until they tired and could no longer escape.
Pwyll figures prominently in the myths surrounding Arawn. Arawn had killed a stag only to find that Pwyll had set his dogs on the kill, and claimed the stag as his own. After some discussion Pwyll admitted that he had been mistaken and Arawn sentenced him to take his place, for a year and a day, in Annwn. Arawn would stay in Pwyll’s place and live in his world, Dyved. During this time Arawn increased the wealth of Dyfed (Dyved) two-fold and Pwyll had some success in Annwn. He managed to slay Arawn’s hated-foe Havgan. It was a task that Arawn had been unable to do himself. After his time was served, the two became friends upon Arawn finding that Pwyll had respected his husbandly-rights and had not bedded Ethne (Arawn’s wife).
Arawn was a member of the Tauatha da Dannan a race of gods worshiped by the Celtic people. He was a medium-sized man weighing 475-pounds. Four-hundred and seventy-five-pounds doesn’t sound medium, but his body mass, as a god, was different from that of mortals. He possessed multiple superhuman powers and ruled over revenge, terror, war, and spirit contacts, and took a somewhat more-gentle approach in magical matters and friendships. He could possess the body of another as when he swapped places with Pwyll, and he could create bits of magical matter.
When Pwyll fell in love with Rhiannon, Arawn produced a bag that could not be filled, no matter what was placed in it. During the time of King Arthur, Arawn had possession of a magical cauldron of regeneration, but Arthur’s men found it and took possession of it.
He fought alongside Bran in the Battle of the Trees, which is believed to have been started by the theft of a dog. Or, more-popularly believed, to have come about when Bran set out to avenge the mistreatment of his sister Branwen by her husband, King Matholwch. Although Arawn and Bran defeated Gwyddion and Amaethon, Bran was mortally wounded.
There is a plethora of Celtic gods, some having given names of foods we eat today such as Bran (a god of agriculture) and others have become marvelous tales for the comic book reader. Each has some basis in reality and each served a purpose, during their time.
Arawn has counter-parts in other mythologies. In Greek he’s Hades, and in Roman myths he is Pluto.