Contained within traditional demonology is a demon or evil spirit known as Eligos, who is a great duke of hell. He also goes by the names of Eligor and Abigor, depending on which translation you have access to. It is stated that this great duke of hell is the commander of sixty separate legions of demons, which makes him one of the premier generals of the forces of darkness. Many state that Eligos is a warrior like demon in nature and that he roams the earth planting seeds of discontent amongst nations and their leaders. His purpose is to provoke total war amongst the nations and he is very skilled in the deceptions and trickery that it takes to fulfill his goals. It is also said that Eligos is often allied with certain earthly kings and lords whom he favors and that he rewards them greatly for carrying out his wicked schemes. Eligos is also favored by dark knights, war criminals, or evil men of war who's hearts are filled with wrath, wickedness, and sin.
The origin of Eligos is often considered to be the Lesser Key of Solomon, a 17th century book of demonology and likely one of the most popular within it's genre. Legend has it that the original copy of this book was written by King Solomon himself, however, this claim is obviously backed by no proof and thus the book is officially listed as having an anonymous author. The book first appeared or surfaced sometime within the early 17th century and due to the stigma attached to demonology at that time in Europe, it is thought that the author decided not to publish his name with it out of fear of being scorned by the public. The Lesser Key of Solomon has several sources for it's base, including the Pseudomonarchia Daemonum which was written by the author Johann Weyer. Some scholars have gone so far as to claim that their isn't a single original word in the Lesser Key of Solomon and that it plagiarizes earlier 15th and 16th century demonology works.
In artistic representations of Eligos he is usually seen as an ugly and wicked looking devil sitting on top of a winged beast. This beast usually has the wings of a serpent dragon and a long coiled lizard like tail. Eligos himself is usually depicted holding a long lance or scepter that is often forked at the end. Other more contemporary works show him as a human like figure, dressed fully in knights armor. Usually draped across his mid section is a long sword and in his right hand he holds a long medieval era lance. It is quite rare indeed to find paintings and drawings for Eligos that do not play into his reputation of being a warrior demon. Several Japanese anime creators have also created figures based on Eligos, however, usually these characters are only loosely based on him and often come across looking like an evil variant of the Seraphim angels. The internet is scattered with many different artistic interpretations of Eligos, so do be sure to check those out.
There is a somewhat bizarre legend regarding Eligos, which is that the semi-skeletal like demonic horse that he rides upon was originally a great steed within the Garden of Eden. This great and noble beast may have even been ridden upon by Adam and Eve before they were cast out for eating the forbidden fruit. Legend has it that after Adam and Eve were cast out of Eden, this great horse died from the spiritual corruption that Adam and his wife brought upon their utopia. While the horse was dead on the ground and decomposing it is said that Satan resurrected him by injecting a great dark force into the rotting horse corpse. The horse stood up with maggots crawling all over it's body and expelled fire from it's nostrils. Lucifer then sent a group of minor demons to tame the evil beast and then to deliver it to Eligos as a gift. It is said that Eligos pleased Lucifer so very much through all his loyalty that he was given this evil renown Steed of Abigor.