The Dawn Era began with the creation of Mundus; it is an era that is known mostly through myth and legend, which are different in different cultures, however most scholars agree on what events led up to the start of recorded history. Time did not exist and when it was created it was not linear, like during a Dragon Break. The Convention took place at the "end" of this era, at the imposition of linear time.
The Merethic Era, otherwise known as the Mythic Era, was the era between the start of linear time and recorded history. The Atmorans came to Tamriel from Atmora; after they arrived, they began to spread throughout mainland Skyrim. When the Aldmer first arrived in Tamriel they initially settled in the Summerset Isles, and then spread eastward into the mainland of Tamriel. As the Aldmer settled Tamriel, they changed culturally in relation to their new environment. The ones who stayed in Summerset Isles became the Altmer; those in Valenwood, the Bosmer; those in Skyrim, the Snow Elves; in Morrowind, the Chimer and the Dwemer; in Cyrodiil, the Ayleid; and in High Rock, a mix between the Aldmer and the Nedes birthed the Bretons. It was a time when all manner of mythological occurrences are said to have taken place. The era was commonly considered to be outside of verifiable history, as humanity did not possess a written language to speak of until the end of the Mythic Era. Aldmeri records, on the other hand, date back to the beginning of Merethic Era.
The First Era began with an expansion of both man and mer peoples, with varying degrees of conflict and accommodation. The Nords were particularly warlike, conquering not only Skyrim but areas of High Rock and Morrowind as well. The First Empire of the Nords ultimately fell to a combined force of Chimer and Dwemer to found Resdayn, but in time they would turn against each other, resulting in the disappearance of the Dwemer and the ascendancy of the Tribunal in the governance of the province. The apparently cordial relations between Ayleid and men in Cyrodiil ultimately broke down, and Alessia led a slave revolt to liberate men in the province, having received a blessing and the Amulet of Kings from Akatosh, the latter of which was to serve as a symbol of Imperial power for most of Tamriel's history. After a period of relative stability, this empire eradicated the remaining Ayleids under the direction of the Alessian Order. The order itself fell during the War of Righteousness, which wiped out both the Order and the Empire. The Second Empire was founded in 1E 2703, when Reman Cyrodiil unified the province to fight off an Akaviri invasion. Victory in this battle brought both the Dragonguard and the Akaviri Potentate to Tamriel. Reman and his descendents then went on to conquer all of Tamriel except Morrowind, founding the Second Empire, which some call a golden age. Reman II began the Four-Score War with Morrowind, which ended the same year Reman III was assassinated by the Morag Tong,1E 2920. Leaving no heirs, the Potentate Versidue-Shaie ruled in his place, and declared the end of the First Era.
The Second Era started after the Akaviri Potentate Versidu Shaie asassinated the last of the Cyrodiil line in 1Era 2920. Facing rebellious nobles building up their own sizeable forces, he used his remaining legions to crush all independent armies and instituted what would become the Fighters Guild as a place to hire mercenaries. He also affirmed the charter to found the Magicians Guild, begun by Vanus Galerion in Firsthold on the Summerset Isles in 2Era 230. Both Shaei and his son were in turn assassinated by the Morag Tong, ending the Second Empire centuries after the death of the last Reman. This began the Interregnum, which lasted for centuries and saw many petty kings attempt to take the throne of Cyrodiil, and other provinces become their own network of independent kingdoms and alliances, if they were not already. The kingdom of Elsweyr was created in 2Era 309, when the Khajit kingdoms of Pelitine and Anequina reconciled their historical differences and the rulling families married. There was a second invasion from Akavir in 2Era 572, landing in Skyrim. It was repelled either by a joint force of Ahrgonians, Duhnmer and Nhords, or by Vivec flooding the land. In 2Era 578, Molag Bal launched an invasion on Tamriel known as the Plane meld, in an attempt to drag Nirn out of Mundus and into his realm of Cold-harbour. Molag Bal was doing this by using devices known as Dark Anchors, but a hero known as the Vestige led an army into Cold-harbour and put an end to his scheme. Also in this era was the Three Banners War, between the Ebonheart Pact, the Daggerfall Covenant, and the 1st Aldmeri Dominion, during which the 3 factions struggled to gain control over Cyrodiil and the rest of Tamriel. The Interregnum ended after Tiber Septim conquered Tamriel, declaring a new era in 2Era 896 to mark the completion of his conquest.
The Third Era was the time of the Septim Dynasty. The early years were mostly peaceful, barring the assassination of Pelagius I. The first major upheaval of the era was the War of the Red Diamond, where Potema Septim tried to claim the Ruby Throne for herself and her son Uriel. This involved parts of Skyrim and Morrowind turning against the Empire, and only ended in 3Era 137, after the Empress Kintyra, Uriel Septim III and Potema were all dead. The later years of the Third Era show in increasing level of political instability across Tamriel. The Camoran Usurper arose in Valenwood around 3Era 253, and conquered Valenwood and Hammerfell with an army of daedra, before being stopped at High Rock in 3Era 267. The imprisonment of Uriel Septim VII and the time of the Imperial Simulacrum brought many more small wars across the Empire as Tharn's governance faltered. Ultimately Tharn was defeated by the Eternal Champion, and Uriel Septim returned to the throne of the Empire. The Iliac Bay area of High Rock witnessed the reactivation of the Numidium and reorganization of the High Rock political landscape in 3Era 417, known as the Warp in the West. A few years later Morrowind was changed by the apparent reincarnation of Indoril Nerevar, and the downfall of the Tribunal. The Oblivion Crisis arose six years later when Mehrunes Dagon, attempted to invade Nurn. This caused widespread devastation, including the destruction of the Crystal Tower. At the beginning of this the current emperor, Uriel Septim VII was assassinated along with all his hairs, save one illegitimate son, Martin Septim. Ultimately Martin destroyed the Amulet of Kings and sacrificed himself to defeat Dagon, bringing the Septim line of emperors to an end.
In 4Ere 5, Lie Rock fell upon Vivec City in Morrowind, causing Red Mountain to erupt. The dual cataclysm caused widespread destruction across the province, reducing many Cities to rubble. In the wake of the eruption, the province was invaded by the Argonians, taking revenge for years of systematic enslavement by the Dunmer. The Fourth Era saw the general decline of the Mages Guild, due to magic's reputation of having started the Oblivion Crisis. Many splinter groups were subsequently formed in many provinces, such as the Synod and College of Whispers. In 4Era 22, the Thalmor resurrected the Third Aldmeri Dominion in the Summerset Isles. In 4Era 29, the Third Aldmeri Dominion invaded Valenwood, overthrew the government and allied themselves with the Bosmer there. In 4Era 98, the two moons, Masser and Secunda, mysteriously disappeared, an incident known as the Void Nights. After two years, the two moons finally returned. The Thalmor immediately announced that they had restored the moons using previously unknown Dawn magicks, so the Khajiit credited the Thalmor as their saviors. The Third Aldmeri Dominion was now composed of the Summerset Isles, Valenwood and Elsweyr. In 4Era 171, the Aldmeri Dominion sent their ambassadors to the Imperial City with an ultimatum. The list of demands included tributes, disbandment of the Blades, outlawing the worship of Talos and the ceding of large sections of Hammerfell to the Dominion. The Emperor rejected the ultimatum, and the Great War began. After a bloody war fought across Hammerfell and Cyrodiil, the Dominion weredefeated at Battle of the Red Ring. Following this battle, the current Emperor, Titus Mede II, signed the White-Gold Concordat with the Dominion in 4Era 175, which was largely similar to the terms initially rejected. Hammerfell, however, continued to fight, and was ultimately renounced by the Empire, and forced the Dominion to withdraw from the province in 4Era 180. A Civil war broke out in Skyrim during the Third Century of the Fourth Era, with conflict worsening following the killing of High King of Skyrim Torygg by Ulfric Stormcloak. Alduin, Nordic God of Destruction and Firstborn of Akatosh, also returned, bringing with him the reappearance of the dragons to Skyrim. However, the Dragonborn ultimately defeated Alduin, averting Tamriel's destruction.