The Rulers of Heaven & Hell
Some are obvious, others are not, it particularly seems to get complex during the portions where the Civil Wars are going on. But in my mind this has always seems like a good way to order them.
Starting with Hell as we first learned about the existence of Hell before the existence of Heaven.
1. Azazel - Seasons 1 & 2
Although it’s never said outright, we are certainly led to believe that Azazel very much runs the show in Hell for the first two Seasons, and the plan that he was trying to fulfill is carried on by the rulers of Hell until Season 5.
We know very little about Azazel’s background and nothing is directly confirmed or stated on the show, although rumors label Azazel as a fallen angel, as the Biblical character himself from the Book of Enoch was just that, and it would explain what the yellow eyes signify.
Killed by: Dean Winchester
2. Lilith - Season 3 & 4
No doubts that Lilith runs the show here. She is the one giving the orders and sending out Demons to break the seals, as well as possessing Dean’s soul after it’s sold to a crossroad’s demon. Lilith has white eyes and is the first Demon that Lucifer created, making her one of the oldest occupants of Hell. The story goes that originally it was Lilith and Adam in the Garden until Lilith was corrupted and God replaced her with Eve. Hence this would make her even older than Cain.
Killed by: Sam Winchester
3. Lucifer - Season 5
Yeah he hated Demons, but the Demons loved him (Crowley aside). Lucifer ruled Hell through Season 5, able to get Demons even to kill themselves at a simple request. Ultimately his game was to wipe out humans and Demons alike, but this ended when Sam threw him and Michael into the bit, trapping all three of them in the darkest prison of Hell (Along with Adam who was being possessed by Michael at the time).
Killed by: Not actually dead, but thrown into the pit by Sam Winchester.
4. Crowley - Season 6, 7, 8, 9?
The first to officially use the title ‘King of Hell’, Crowley quickly resumes control of Hell following Lucifer’s return to the pit. Unless we have been misled and there is something different about him to, then Crowley is the first normal Demon to become King of Hell. Unlike his predecessors Crowley has more interesting in maintaining a balance between Hell, Earth and Heaven, by simply managing the Crossroads, if a human summons them and signs away their soul, provided Hell keeps up its end of the bargain then it’s all fair game, as he would see it. But Crowley also likes to meddle in the affairs of Earth and Heaven, often with one eye and informants in both. While in Season 6,7 & 8 he seems to love his job, this starts to waver a little from Season 9 onwards. He appears to still want to be King of Hell, but prefers spending time on Earth and with the Winchesters. Going AWOL from Hell quite a few times in these two Seasons.
Removed: Loses control of Hell after being kidnapped by the Winchesters and becoming addicted to Human Blood.
5. Abadon? - Season 9?
Crowley certainly makes his return to the position by the end of the Season, but for a while Hell is split between them and Abadon certainly seems to control more of actual Hell itself during this time as Crowley spends very little time there. Crowley didn’t regain his position through the support of the Demons, he simply took it back after he helped the Winchesters to kill Abadon.
Killed by: Dean Winchester
6. Crowley - Season 10
Back on the throne now Abadon is gone, Crowley appears to have less interest in it now, rather neglecting his job and showing disdain for the other Demons in favor of the Winchesters.
Heaven became something we were aware of in Season 4, prior to that being told there was no such thing as Angels, Heaven or God.
1. Michael - Season 4 & 5
The oldest of the Archangels, it seems to have been that Michael has ruled Heaven since God left, with the help of Zachariah at his right hand. Michael very much drove the idea of getting the Apocalypse on track, where he could possess Dean and Lucifer would possess Sam and he would ultimately win by having to kill his brother. Michael in the end possessed the Winchester’s younger brother Adam instead and was thrown into The Pit with Sam and Lucifer at the end of Season 5.
Killed by: Not actually dead, but thrown into the pit by Sam Winchester.
2. Raphael - Season 6
One of the other Archangel brothers, and apparently (at this point) the only one either alive or free from the Pit, Raphael plans to free his brothers from The Pit and restart the Apocalypse, apparently just continuing the regime of Michael before he is killed by Castiel. This is a Civil War period though, even though while alive Raphael controls Heaven, Castiel has the loyalties of many other Angels who rebel against Heaven to join him.
Killed by: Castiel
3. Castiel - Season 6
Having been brought back by God he takes it upon himself as a sign that God has work for him, and that work is in taking control of Heaven. Cas works alongside Crowley to secure both their positions as rulers of their realms to get into Purgatory and absorb the souls there to essentially make their position unchallengeable. This backfires and Cas absorbs all the souls, including the Leviathans that sneak along for the road and escape into Earth after apparently having killed Castiel, but not before he kills Raphael.
Removed: Vanished after killing Raphael
Season 7
All goes quiet in Heaven during Season 7, though with the disappearance of Castiel and the death of Raphael, we learn that Heaven has thrown itself into turmoil, unsure what to do now the Archangels and their only alternative hope of Castiel are gone. At some point here, Naomi seems to manage to take control.
4. Naomi - Season 8
Her position is not secure, and we learn that the Civil War is still raging in Heaven around her, but Naomi appears to be sitting on top for now. She doesn’t appear to be focused on returning to the Apocalypse, more in just returning Heaven to normal and bringing about the bureaucratic peace that they need. She uses Castiel, brain washing him to get him to assassinate Dean and collect the tablets for her, before Crowley gets his hands on them. Naomi’s allegiance is a little gray, as while she did try to get Cas to kill Dean, she has a change of heart remembering that the mission of the angels was to try and protect humanity, and ultimately tries to warn them about Metatron, before being killed herself by him.
Killed by: Metatron
5. Bartholomew - Season 9
After the Angels fall, Bartholomew appears to secure control, helping the angels to secure vessels and setting them about working under him. Bartholomew still sees Castiel as a threat though and attempts to persuade him to join sides with him, when he refuses Bartholomew tries to kill him, only to be killed by Castiel instead. Many of the angels that worked for Bartholomew join with Castiel after this.
Killed by: Castiel
6. Metatron - Season 9
Initially happy to just have Heaven to himself, it isn’t until a little later in the Season Metatron sets his eyes on ruling.
Again things become a little flaky here as Heaven again splits between Castiel and Metatron, variating between sides and numbers. But Metatron controls Heaven which would put him in a more secure position as Ruler, particularly as Castiel himself states that he doesn’t want to rule - fearful that he’ll repeat what happened in Season 6.
Rather than just ruling Heaven, Metatron attempts to become the new God by channeling the power of the Angel Tablets and trying to write his own story. He is brought down but not killed, instead being seized by the Angels when they turn against him after revealing his terrorist attacks to make Castiel look bad. He now resides in the prison of Heaven.
Removed: Locked in the Prison of Heaven by the other Angels.
7. Castiel? - Season 10
Again it’s a little uncertain here as Castiel doesn’t want to rule and the angels appear to be working in more of a commune way with no distinct Leaders, but Castiel does seem to call the shots, if he says 'Stop’ the angels are meant to stop, when he says 'Go’ they’re meant to go, Castiel seems to have this conviction as do a few of the others - perhaps proving ultimately that with the exception of a few odd angels, most really do only know how to take orders.