The Elder Scrolls Lore

The Dawn Era

"In Mundus, conflict and disparity are what bring change, and change is the most sacred of the Elven Forces. Change is the force without focus or origin." — Oegnithr

The Creation of the World
     In the beginning, there was nothing. No life, no death, nor dark or light; only emptiness and nonexistence. Then, two beings arose out of the nothingness; Anu and Padomay. Anu was a being of order, stasis, and light, while Padomay was a being of chaos and change. These two beings were equal yet opposites; always fighting against each other yet neither were able to win.
     To better reflect and understand themselves, both beings created their own soul. Anu's soul became known as Anui-El, the soul of all things and everlasting light. Padomay's soul became known as Sithis, the soul of nothingness and void.
     Since both Sithis and Anui-El were still both equal and opposite, they came to an agreement and created a set of rules, which initially birthed the universe, also called Aurbis. Aurbis was unstable however, so Anui-El made it stable by creating the concept of time. With the Aurbis no longer chaotic, lesser beings, or gods and goddesses, also known as the Aedra and Daedra, came into existence. Along with the new Aedra and Daedra, planes of existence also came to be for these beings to inhabit.
     These inhabitants were called Aetherius and Oblivion. With the universe now stable and inhabitable, Sithis, being Anui-El's opposite, decided to try and undo the lighter-being's work and return the universe to chaos and turmoil. In order to do so, Sithis went to the lesser-gods, who were disappointed in their choices of Aetherius and Oblivion, and proposed to make another plane of existence. This plane was known as Mundus.
     But unlike Anui-El and Sithis, the lesser-gods were not infinite beings with an opposite and equal force, so when inhabiting Mundus, pieces of themselves were given up when they tried making their own creations. This made the Aedra and Daedra less powerful. Many of the gods and goddesses realized this, so they tried returning to Aetherius or Oblivion before the creation of Mundus was complete. For the ones that escaped, they tore holes through the planes, creating the sun and the stars.
     For those who did not escape, they gathered together to decide Sithis's punishment for convincing all of them to create Mundus and drain their power. It was decided that Sithis would have his heart removed and it would be destroyed. However, it was discovered that his heart couldn't be destroyed. So Anui-El buried Sithis's heart in the sea. The heart was so powerful that it created a mountain, now called the Red Mountain, around itself.
     With some of the gods still confined to Mundus, yet having enough power to continue being mighty gods and make their creations, they became known as the Eight Divines. The Eight Divines created their own realms within Mundus. For the rest of the group of lesser-gods that had lost most all of their power resorted to procreation, thus creating the men and mer of Nirn.
     The descendants of these now mortal gods spread across the face of Nirn, and began the legacies of Tamriel. Thus, the Dawn Era, and life itself, began.
There are many different beliefs of how Nirn and life on it came to be. Different races with different religions believe in their own versions of the creation of Nirn, giving Anui-El and Sithis along with all the other gods, other names. However, that is the gist and very basic understanding of how the world came to be.

The Elder Scrolls
     Golden-encased, spell-protected pages filled with prophecies, stories of past and present events, and words upon words of foretold events are known throughout Tamriel as the Elder Scrolls. It's unknown where they came from, who wrote them, or how many of them exist in the world. Some say the Aedra created them, some say they were written by the first men and mer, but no one knows for sure.
     The scrolls contain many prophecies of foretold events, often mysteriously telling of a hero that will resolve such events of great turmoil. However, simply reading the scrolls cannot be done. Monks known as Moth Priests attempt to read them, but often at a price. The side effects of reading the scrolls often result in blindness, insanity, or even death.
     What knowledge that has been obtained by the scrolls tells of many different prophecies, all that have been or will be fulfilled. The Tyranny of the Sun prophecy stated that a legendary bow will purge the world of sunlight allowing vampires to roam unhindered, the Nerevarine Prophecy that told of a prisoner born on a certain day to uncertain parents would be sent to Morrowind to eventually unite the province, and the Dragon Crisis prophecy that told of the coming of Alduin the World Eater were all foretold in the scrolls.
     There are an unknown amount of Elder Scrolls in the world, but few scrolls are known by many, even though their whereabouts are uncertain and change through the centuries. The Elder Scroll Oblivion, Elder Scroll Dragon, Elder Scroll Blood, Elder Scroll Sun, Elder Scroll of Alma Ruma, Elder Scroll of Altadoon, Elder Scroll of Chim, Elder Scroll of Ghartok, Elder Scroll of Mnem, and Elder Scroll of Ni-Mohk are the few that are known to exist.
     No matter how the scrolls were made or how they got here, it is one of the most sought after and important artifacts on Nirn. Though only few have held them in their hands, everyone knows they are out there somewhere, ready to tell the story of a new hero destined to do fate's work.

Man Is Home
After the gods-turned-mortal populated the lands, they became the men, mer, and beastfolk that live in Tamriel now. Each slowly became its own race, and made its own civilization with its own rules. The Altmer, or High Elves, are native to Summerset Isles. The Bosmer, or Wood Elves, are native to Valenwood.
The Dunmer, Dark Elves, are natives of Morrowind. Bretons are natives of High Rock, along with most Orsimer, or Orcs. Redguards are from the lost continent of Yokunda, and now reside in Hammerfell. Nords are descendants of an ancient race called Atmorans, who now call Skyrim their home. Argonians are reptilian-men native to Black Marsh, Khajiit are cat-folk native to Elseweyr, and Imperials are natives of Cyrodiil, which is also the seat of the Empire.
Each race has its own rich history, along with other races that are lost to the ages. They inhabit their own countries and govern their own provinces, but none are scared to war with the other races, or even their own kin. Each race has its own unique characteristics as well, helping them thrive in the places they call home. Whether it be resistance to the cold, or a high tolerance to disease.
Regardless of where each person is from, they have their own beliefs and ideals. To each their own, and to each corner of the world they will go.

Conclusion
The rich history of Tamriel, or Nirn itself, is a very vast topic, with thousands upon thousands of stories to tell. Past, present, and future. Not only that, but every story has a different side, a different version, a different outlook on the outcome. Some stories are written in books or ancient text, others are just passed down by being told.
Covering all of the history of Tamriel would take books upon books to complete, but as for some tales, keep reading to hear them.

Official Elder Scrolls Lore