On Talos, Tiber Septim, or Hjalti Earlybeard.

There are few things all agree on concerning Tiber Septim.
The first is that he was Man, though whether he was Nord or Breton is questioned. The second is that he conquered Tamriel, through war, threats and agreement, and so founded the Third Empire, which lasts to this day. The fourth, and final agreed fact is that he was Dragonborn, as I am.

The more popular, orthodox belief holds that he was born Talos of Atmora. The Greybeards, masters of the Voice, told him he would come to rule all of Tamriel, but he must go south to do so.
He joined the then-king and later emperor Cuhlecain, and served as General Talos under him.
He fought in the battle of Sancre Tor, against a force of Bretons and Nords. The Nords, upon seeing his use of the Voice, the Thu'um, saw he was a true son of Skyrim and knelt before him, but the Bretons did not. In the year 854 of the second era, a Bretonic Nightblade attempted to kill him and succeeded in killing the emperor. Though alive, Talos' throat was slit, and he could no longer Shout. He later took the name of Tiber Septim, and took charge of Tamriel. His line continued to the day Martin Septim sacrificed himself to oust Mehrunes Dagon from Tamriel at the end of the Oblivion Crisis.

The other belief, considered Heresy by those holding to the more orthodox way of thought, holds that he was born Hjalti Earlybeard of Alcaire, an island in High Rock. A Breton. Those who believe this theory believe that Wulfarth, an ancient King of the Nords who died at the battle of Red Mountain and desired nothing but the death of the Tribunal, also known as Ysmir Underking, helped Hjalti during a battle taking place at Old Hrol'dan, taking the form of a storm and protecting him from arrows as he shouted down the walls. It is this, they believe, that earned him the name Talos, Stormcrown in old Ehlnofex. With these allies, Ysmir Underking and Cuhlecain, he takes the eastern lands of Cyrodiil in under a year, and march east.

The Dunmeri Battlemages surrender before them, and they take the Citadel. Cuhlecain was set to become emperor, but before he was officially crowned, Hjalti had him assassinated, and slit his own throat to rule himself out as a suspect. He then blamed enemies of the late king, and was crowned emperor himself by Zurin Arctus, the Grand Battlemage. He sends Ysmir to take Skyrim for him, but to make sure it did not seem he (Hjalti) was in two places at once, Ysmir had to work behind the scenes.
The newly crowned and renamed Tiber Septim takes Hammerfell through trickery, supporting the losing side in a civil conflict to be invited in and seemingly legitimise his rule.

His later conquests are made possible by the Numidium, the Mantella, the weapon the Dwemer sought to create using the Heart of Lorkhan. It was once destroyed by Wulfarth, and now Hjalti betrays Wulfarth, the Underking, and Zurin Arctus, the Battlemage, by using Wulfarth's soul to power the Numidium, and accusing the Battlemage of attempting to kill him. Later, a rotting undead Mage who controls the skies destroys the Numidium, though it crushes him as it falls.
Even later, after Tiber Septim's death, Pelagius the first takes over, and though nervous, he has a good advisor. A man arrived at the door. "I was friends with your Grandfather," the Underking said, "he sent me to help you run the Empire."

Those are the differing tales on how he came to be Emperor of Tamriel, but what is more contested today than ever than his divinity? Men have revered Tiber Septim as a Divine for ages past, a possible aspect of Lorkhan himself, who granted Men life. The Divine of Governance and Law, God of Men. But after the Great War, slightly over three decades ago, and its ending with the White-Gold Concordat, Men and Elves have been forbidden from worshipping him as they would, leading to Hammerfell leaving the Empire and Ulfric Stormcloak attempting his revolution.

The Thalmor claim that revering him as a Divine is blasphemous, an affront to the true Divines. They are actively suppressing the honouring of Talos where they can, and those, in Skyrim at least, who are too open about the faith are like to be hauled off to Northwatch Keep to be 'retrained'.
This the only reason I regret aiding the Empire in the Civil War, and I make no secret of my disagreement with the Thalmor. In fact, if one were to check my basement in Lakeview Manor, one would be either shocked and horrified or ecstatic at the amount of second-hand Thalmor Justiciar robes and Elven armour I have... collected... over the years of this disagreement. They still attempt to execute me, of course. Growing my collection bit by bit.

I believe firmly that Talos ascended to Divinity, and I know that the Thalmor hold this same belief, despite their actions. They also believe, unlike me, that through persecuting and murdering his followers on Nirn he will be unmade, thereby destroying another Tower, bringing Nirn one step closer to destruction. I believe this is incorrect; if Nirn itself has accepted him as a Divine, there is little effect Man's belief can have on this.

As was mentioned in an earlier volume, Talos is also one of very few beings to have achieved CHIM, Royalty. He used this when he removed the jungles that once covered Cyrodiil from existence so entirely that there is no record of them outside of his removal of them. His erasure of the jungles of Cyrodiil was not merely causing them to disappear from the present, but from the past as well. As was written in Mankar Camoran's commentaries on the Mysterium Xarxes, volume three if I recall correctly, "Chim, those who know it can reshape the land. Witness the home of the Red King once jungled."
The Red King is Talos, his home Cyrodiil.

- From the Journals of the Dragonborn, Volume twenty.

As a translator and scholar. I must not that much of what is written in the section on Hjalti is almost identical to recovered parts of a book named 'The Arcturian Heresy'. We had not believed that book to be that old, but the similarities are too striking to be coincidental, so we must assume that 'The Arcturian Heresy' was written either before or shortly after these journals were written; more likely before, as these were likely never published. I sincerely doubt even the Dragonborn had the political clout to openly admit to murdering official enforcers of the Aldmeri Dominion!

Author's note: Well, here's the next one! Thank you very much for your reviews and suggestions, more of which are always welcome! If you spot any mistakes, tell me, I may or may not correct them (I am but an adventurer, after all, not a scholar!), but I would appreciate any comments. Oversights, on the other hand, I will correct if pointed out.