Key info will be in bold but to truely understand the theory I recommend reading it all (Yes I know there is a lot)
Okay. Where to start? Well we're going to cover everything I came across that allowed me to come to this conclusion so I guess it doesn't matter where we start from.
We'll start where it all started with the Aedra.
Now let's move on to a specific Aedra named Lorkhan because he plays a key role in all of this.
According to legend, Lorkhan approached his peers (the Aedra) with a plan to create a new plane of existence, and to create and populate it with lesser beings of their own design. He was able to convince a group of his fellow spirits to help with his plan, while others suspected a trick or were simply uninterested and were kept out.
Lorkhan's plan was executed, resulting in the creation of the mortal plane/planet of Nirn.
After the world was materialized, Lorkhan is separated from his divine center, involuntarily, Altmer legend details the anger the remaining Aedra had towards Lorkhan once Nirn had been created. As punishment, they imprisoned him and tore out his heart, intending to destroy it. However, the Aedra were present on Nirn, and Nirn itself was the remnants of Lorkhan's body. (Thus his Nordic Moniker of God of the Underworld) His Heart was literally the Heart of the World, and it could not be destroyed. Instead, the Aedra threw the heart down to earth, intending to bury it forever.
So the world of Nirn was created... And the Aedra doomed Lorkhan to the underworld, Nirn.
- The Mer believed themselves to be the literal descendants of those beings (the Aedra), and believe they were robbed of their immortality by Lorkhan, whom they reviled as a trickster. To the High Elves, he is the most unholy of all higher powers, as he forever broke their connection to the spirit plane. The Mer are seeking always to bridge the gap between mortality and divinty.
- Men believed that they were created from nothing by the et'Ada responsible for Nirn, and thus considered their existence a gift and Lorkhan a hero. Men do not believe themselves to be descended from the Aedra. They believe themselves to be created from nothing by Lorkhan, (See below) and thus owe their entire existence to him. In their opinion, Lorkhan is the hero of mankind, and they object to his mistreatment by other races (Mer/Elves) They know him as Shor (God of the Underworld).
In the legends, he is almost always an enemy of the Aldmer and, therefore, a hero of early Mankind.
So to Mankind, and the Nords specifically, consider Lorkhan, or Shor as they know him, the Hero of Mankind. Atmoran myths depicting him as a bloodthirsty warrior king who leads the Nords to victory over their Aldmeri (the early elven race that through cultural diffusion evolved into the various present day Mer/Elves)
One Major Example of this being when...
Orkey is a loan-god of the Nords, who seem to have taken up his worship during Aldmeri rule of Atmora. Nords believe they once lived as long as Elves until Orkey appeared; through heathen trickery, he fooled them into a bargain that 'bound them to the count of winters'. At one time, legends say, Nords only had a lifespan of six years due to Orkey's foul magic.
Shor, the Nordic version of Lorkhan, showed up, though, and, through unknown means, removed the curse, throwing most of it onto the nearby Orcs.
Lorkhan/Shor takes the side of Men and saves them from a curse. Could he be the one who steps up, either indirectly or directly, in Skyrim and saves them again?
Let us continue...
Ysgramor is a ancient Nordic king who was first to land in Skyrim at Hsaarik Head, fleeing civil war in Atmora. When the Nords arrived in Tamriel, they befriended the Falmer (Snow Elves). After a while, the elves noticed the steep population growth of the newcomers, and thought they were a threat to the Elvish civilization. The Nords were hunted down until only Ysgramor and his two sons survived, who then fled back to Atmora. Only later to return with the legendary Five Hundred Companions and drive the Elves from Skyrim.
It may be that the exploits of the near-mythical Ysgramor conflate the reigns of several early Nord Kings, as the Elves were not finally driven from the present boundaries of Skyrim until the reign of King Harald, the thirteenth of Ysgramor's line, at the dawn of recorded history, The First Era.
King Harald was the first to relinquish all holdings in Atmora (Until that time, the Nords of Atmora and Skyrim had been considered the same group), proclaiming that the people of Skyrim were an independent people. All humans on Tamriel are descended from these Nords, although some bloodlines run thin. And it's safe to say all humans on Nirn because expeditions to Atmora in the Third Era describe a place of permanent winter, with little life and no signs of human habitation and the Tsaesci or Vampire Snake people ate the men of Akavir long ago.
So the Falmer have a direct history with the Nords and they were defeated before by them.
The Falmer occupied Skyrim until the late Merethic, when the final wave of Nordic immigration, led by Ysgramor's clan(see above), finally drove out the mer.
Notice they don't necessarily say they were killed off or extinct but rather just drove out of Skyrim.
The Altmer in Raven Rock claim that the Snow Elves (Falmer) have blended with the other elven races through interbreeding.
The Book http://www.imperial-library.info/content/oblivion-fall-snow-prince, found in a burial barrow, seemingly supports the second hypothesis, describing the fall of the Snow Prince, an elven leader who faced the Nords in the Battle of Moesring.
Some excerpts...
The Battle of the Moesring was to be the final stand between Nord and Elf on our fair island. Led by Ysgramor, we had driven the Elven scourge from Skyrim, and were intent on cleansing Solstheim of their kind as well.
...
From whence he came we did not know, but into the battle he rode, on a brilliant steed of pallid white. Elf we called him, for Elf he was, yet unlike any other of his kind we had ever seen before that day. His spear and armor bore the radiant and terrible glow of unknown magicka, and so adorned this unknown rider seemed more wight than warrior.
...
The Elves, spurred on by the deeds of the Snow Prince, rallied together for one last charge against our ranks. It was then, in a single instant, that the Battle of the Moesring came to a sudden and unexpected end.
Finna, daughter of Jofrior, a lass of only twelve years and squire to her mother, watched as the Snow Prince cut down her only parent. In her rage and sorrow, Finna picked up Jofrior's sword and threw it savagely at her mother's killer. When the Elf's gleaming spear stopped its deadly dance, the battlefield fell silent, and all eyes turned to the Snow Prince. No one that day was more surprised than the Elf himself at the sight that greeted them all. For upon his great steed the Snow Prince still sat, the sword of Jofrior buried deeply in his briast. And then, he fell, from his horse, from the battle, from life. The Snow Prince lay dead, slain by a child.
...
With their savior defeated, the spirit of the remaining Elven warriors soon shattered. Many fled, and those that remained on the battlefield were soon cut down by our broad Nord axes.
...
So ends this account of the Battle of the Moesring, and the fall of the magnificent Elven Snow Prince. May our gods honor him in death, and may we never meet his kind again in life.
And lastly a scholar who traveled to Solstheim (circa Nerevarine) in search of these elusive beings validates the Fall of the Snow Prince Book by finding proof.
This is from the http://www.uesp.net/wiki/Bloodmoon:In_Search_of_the_Falmer.
Take everything, including the book, which is the proof that Athellor wants. The book Fall of the Snow Prince is an account by Lokheim of a glorious battle between Nord and Elf at the foot of the Moesring Mountains, the Snow Prince's death and his unusual burial in this very cave. After reading the book, you'll get a journal entry, then return it to Athellor and receive 800 gold in reward.
Through that quest It is revealed, contrary to Nordaic myth, that the Rieklings are not the ancient and proud race of the Falmer but are different entirely. The Falmer themselves left Solstheim and became mixed with the other races of the elves, thus vanishing from Tamriel save in the blood of their various descendants amoung the other elves.
So I personally don't believe we've seen the last of the Falmer and they have more motive against the Nordic people, in specific, then any Akaviri race does.
Plus...
Remember all the Mer are seeking always to bridge the gap between mortality and divinty.
The Elven Akatosh known to them as Auri-El (King of the Aldmer):
In his only known moment of weakness, he agreed to take his part in the creation of the mortal plane, that act which forever sundered the Elves from the spirit worlds of eternity. To make up for it, Auri-El led the original Aldmer against the armies of Lorkhan in mythic times, vanquishing that tyrant and establishing the first kingdoms of the Altmer, Altmora and Old Ehlnofey. He then ascended to heaven in full observance of his followers so that they might learn the steps needed to escape the mortal plane.
What are these steps they must learn to escape the mortal plane of Nirn and achieve divinity?
To kill Man is to reach Heaven, from where we came before the Doom Drum's (Lorkhan) iniquity. When we accomplish this, we can escape the mockery and long shame of the Material Prison.
To achieve this goal, we must:
1) Erase the Upstart Talos from the mythic. His presence fortifies the Wheel of the Convention, and binds our souls to this plane.
2) Remove Man not just from the world, but from the Pattern of Possibility, so that the very idea of them can be forgotten and thereby never again repeated.
3) With Talos and the Sons of Talos removed, the Dragon will become ours to unbind. The world of mortals will be over. The Dragon will uncoil his hold on the stagnancy of linear time and move as Free Serpent again, moving through the Aether without measure or burden, spilling time along the innumerable roads we once travelled. And with that we will regain the mantle of the imperishable spirit.
The Ysmir line is dead and so is His stranglehold on the mythic.
- http://www.imperial-library.info/content/forum-archives-michael-kirkbride
First I want to point out. Ysmir is the Nordic name for Tiber Septim (Talos) Ysmir (Dragon of the North): The Nordic aspect of Talos. He withstood the power of the Greybeards' voices long enough to hear their prophecy. Later, many Nords could not look on him without seeing a dragon.
What about the last line about the dragon(s)?
I'll let you interpret what they mean.
- It could mean the Tamrielic dragons and Dragonlings have been released because Talos and the Sons of Talos have been removed (all dead) and thus the dragons are free to do what they please, possibly attack the Nords, as they no longer are bound to the Cyrodiil Empire.
- It could mean Auri-El is released because the Talos line has been removed. Auri-El being the Elven Akatosh (who we've seen in Dragon form in Oblivion) Making Alduin the Nordic name for Akatosh the enemy of the game, along with the Mer.
Alduin's sobriquet, 'The World Eater', comes from myths that depict him as the horrible, rauaging firestorm that destroyed the last world to begin this one. Akatosh was the first of the et'Ada to form an identity, bringing with him the concept of Time. And the "uncoil his hold on the stagnancy of linear time" line could have something to do with that.
The Nord's know Alduin as a terrible, ravenous dragon who presides over the cycle of existence and devours the universe at intervals. Alduin's coming is feared by all pious Nords, and he is the object of (through Nordic eyes) perverse worship by the Altmer, who venerated Auri-El. Nords therefore see the god of time as both creator and harbinger of the apocalypse. - Lastly and this could be combined with the above suggestion too maybe. The dragons that we know are to appear in the game could just be Tamrielic dragons, that do exist! But instead of being an enemy they could be friendly, as different accounts of lore have suggested.
The interesting bits of info I could find on Tamrielic Dragons on their existence.
All of the dragons didnt die. They have their own means of remaining "hidden" from Tamriel's populace. Whether its shapeshifting, hiding deep in the mountains or jungles, or even in very protective custody of secret Imperial strongholds, they do exist.
The reason the dragons left Morrowind was because of the food chain being broken. Cliffracers were in such great numbers that they food became scarce for the dragons, so they moved on. Even if they stuck around and killed the cliffracers off, the food would still be at a shortage.
- http://www.imperial-library.info/content/forum-archive-gt-noonan
Also there was a population of Dragons that fled the continent of Akavir to the continent of Tamriel because they were being hunted and eaten by the Tsaesci…
The meaning of term "eaten" as given from what is known of the land of Akavir is not clear. Although description of the Tsaesci might suggest literal meaning, it could be a metaphor for being subdued. In Mysterious Akavir by anonymous writer, the Tsaesci are told to have: "tried to eat all the Dragons. They managed to enslave the Red Dragons, but the black ones had fled to (then) Po Tun."
A great war raged across the land, leaving all the black dragons and all but a few red dragons dead. The remaining red dragons retreated to Tamriel, where they were supposedly given refuge in Cyrodiil.
"It was rumored that they moved closer to Cyrodiil, and it may be for this reason that dragons are sacred to the Empire. The legends tell of their aid during wars in exchange for shelter. The avatar of the chief deity of the Nine Divines Akatosh, is a golden dragon. Its relation, if any, to the Tamrielic dragons is unknown - but many stories tell of Akatosh co-mingling with and organizing groups of dragons, although this representation may be metaphorical. If dragons still exist at all, they are never encountered by the mortal races. It has been suggested that they may be able to shapeshift in order to disguise themselves.”
- http://www.uesp.net/wiki/Lore:Dragons
That's where I got the hint that it could be a combination of idea 2 and 3.
"As far as the Empire actually being in alliance with dragon's, there are many hints that lead on to this. Lord Richton was able to summon the Imperial Dragon, N'falilaargas for support in the Battle of Stros M'kai. The Battlespire incident. http://www.imperial-library.info/content/nafaalilargus. In Daggerfall you can face young dragons, called Dragonlings.
The look of the Imperial crest. Even the rumors that Tiber Septim WAS a dragon, shapeshifted into human form. Oh, dragon's exist, and there is proof that they do, but in what quantities? Hmmm.…”
[indent][indent]"Historically Dragons lived in and around isolated villages, located high in mountain ranges. If any of these settlements still exist they remain undiscovered. The villages were aptly situated in areas that allowed both free flying without obstructions and flats for raising cattle. Dragons were known to keep deer and other animals for food, and their meals would simply involve flying low over a ranch and swooping down upon one of them. Dragons were also known to maintain lairs - usually in derelict mining tunnels - safe from thieves and other aggressors."
So is it just the Falmer or a United Mer Empire?
While the Aldmer as a race are no longer in existence on Nirn, the concept of a single, unified elven race has persisted through the eras. The Altmer and Bosmer formed what is termed the Aldmeri Dominion during the second era, uniting the disparate races against a common enemy. Many Imperial historical sources use the term Aldmeri as a synonym for elven, a practice that is certainly not discouraged by the mer themselves.
Current upheavals in the Summerset Isles and Morrowind, particularly against human rule of the continent, may lead to a revival of Aldmeri culture in the near future. - http://oblivion.wikia.com/wiki/Aldmer
I think the storyline of Skyrim will be based around, [u]The Mer genocide of Man.
To followe the steps so that they may bridge the gap between mortality and divinty.
That is who I think will be the main enemies in Skyrim. Some Elven/Mer race (Possibly Falmer who the Nords have defeated before) or a united Aldmeri Dominion against Mankind.
And since Lorkhan(Shor) plays such a role in this theory I thought I'de mention this tidbit as this person could be in the game as well as a villain or friend.
In Skyrim Hrothgar and Whiterun, once places with powerful economies, have been crippled by floods, droughts, and fires, along with attacks from frost trolls and bandits. The area is now under the control of Jsashe, the leader of the local witches coven, and a self-proclaimed priestess of Lorkhan, although the area is still struggling.
Shout out to TES_Boethiah for introducing the idea of the Falmer or Mer being "they" to me and getting the ball rolling on this idea.