Which one of the two wielded the most power? Master or understudy? There seems to be different schools of thought on this. for example from 'Morgoth's Ring', Myth's Transformed', Essay #7, Page 394: 'Sauron was 'greater', effectively, in the Second Age, than Morgoth at the end of the First. Why? Because, though he was far smaller by stature, he had not fallen so low. Eventually, he also squandered his power (of being) in the endeavour to control others. But he was not obliged to expend so much of himself To gain domination over Arda, Morgoth had to let most of his being pass into the physical constituents of the earth...' Therefore, the term, 'Morgoth's Ring'. The earth, Arda, was Morgoth's Ring in which Morgoth had poured his power, just as Sauron poured his power into his Ring. And, just like Sauron, Morgoth's power was no longer in himself. But unlike Sauron, Morgoth could never recover his Ring and slip it back on his finger...... Furthermore, we have this to add to the debate: Morgoth could no longer change shape. He had lost that ability at the time of the slaying of the Two Trees, yet Sauron could and often did change shape up until going down in the Drowning of Numenor. Morgoth no longer had the strength to fight Ungoliant because of 'the power that had gone out of him' The Silmarillion says he had to rely on his Balrogs to rescue him - And 'Myths Transformed' #8, Page 410 says 'Morgoth had corrupted many spirits - some great, as Sauron, some less so, as Balrogs.', so the Balrogs had not the might of Sauron even, although 7 of them were together that saved Morgoth from Ungoliant. Also, Morgoth, a Vala, no longer had the power to asail Arien, the Maia that carried the Sun. Finally, Morgoth even feared to fight Fingolfin, whereas Sauron took out Finrod in Minas Tirith.... If we look, we have only one instance of Morgoth using magic in the First Age: When he binds Hurin to the chair by magical force and makes him see through his own eyes for 27 years. Powerful indeed I must admit. Meanwhile, Sauron, as Morgoth's first Lieutenant, in a limited role along with the Balrogs, Glaurung, the werewolves & orcs, is seen creating a phantom of a dead wife to ensnare one of Barahir's 11 companions, defeating the mighty Elf Finrod in a song of power, fighting the mighty hound of the Valar Huan as a werewolf (albeit in a losing cause) and shifting shapes constantly. After this, we see him deceive the Elves into making the Rings of Power, then gain control over the Nazgul with Nine of them, set up as his own Dark Lord & conquer most of Middle-earth and then encompass the Fall of Numenor through guile... Makes for an interesting discussion.