Tiber Wars

The Tiber Wars were a series of wars during the Second Era which lasted for 42 years, at the end of the Tiber Wars, the Third Era started and Tamriel stood united under the Imperial banner.

Background
The Tiber Wars were inspired when the Greybeards told Tiber Septim that he was destined to become the Emperor of Tamriel. After the death of Cuhlecain, Tiber Septim took his role, and started his conquest of Tamriel in the 855th year of the Second Era. Tiber himself, however, found the initial administration of a fully united Cyrodiil a time-consuming task, and, because of this, the Underking dealth with the Imperial expansion into Skyrim and High Rock.

Skyrim
Despite Skyrim's armies swearing loyalty to Tiber Septim after their defeat at Sancre Tor, Skyrim itself had not joined the Empire during Cuhlecain's rule. Tiber Septim invaded Skyrim with his Legions, one of his commanders was known as Beatia of Ylliolos, and had been ambushed by the Nords after a meeting with the Emperor. The exact date as to when Skyrim fell to the Empire is unknown, but it is known that it was prior to 2E 862, since that is when Thassad II died and Septim invaded Hammerfell.

High Rock
High Rock had lived on pretty well after the fall of the Reman Empire, but due to it existing of multiple kingdoms, it was easily conqeured by Tiber's armies. The official date on which High Rock got conqeured by the Empire is also unknown.

Hammerfell
Hammerfell was the last of the human kingdoms to fall to the Empire. Since the death of High King Thassad II, Hammerfell had been plagued by a civil war between the Crowns and the Forebears, the major political factions of Hammerfell. When the civil war was slowly being won by the Crowns, the Forebears signed a pact with Tiber, allowing his armies to march into Hammerfell, crush the Crowns and claim Hammerfell as his own. The Imperials conqeured Hammerfell with ease, with the Battle of Hunding Bay being the only event where the Crown forces matched the might of the Empire, because of this, Amiel Richton, commander of the New West Navy, decided to send Nafalilargus to deal with the remaining Crown forces. After the Imperial victory, there was a succesful rebellion on Stros M'kai, followed by a rebellion in Sentinel. As a result of the rebellions, Tiber Septim came to Stros M'kai and negotiated the terms of the Treaty of Stros M'kai with the rebel leader of Stros M'kai, Iszara and the rebel leader of Sentinel.

Black Marsh
When the invasion of Black Marsh occured is not known, but it is known that there was fighting between the Legions and the Argonians in 2E 861, it is also known that Black Marsh fell prior to Hammerfell. It was said that Tiber Septim himself thought twice before conqeuring Black Marsh, the border regions fell easily to his Empire, but he wisely decided to avoid strategically unimportant inner swamps, and thus met with little resistance. Even under Imperial rule, the inner swamps were still controlled by the Argonians while the Empire controlled the coasts and borders of the province. Black Marsh joined the Empire mainly through a treaty.

Morrowind
Morrowind became an Imperial province after Hammerfell had fallen. Initially, the Temple and the Great Houses of Redoran, Dres and Indoril wanted to fight until the death, with Telvanni remaining neutral and House Hlaalu proposing accomodation. There were several battles between Morrowind and the Empire, one of which laid waste to Mournhold, now called Almalexia. The situation changed, when Vivec appeared and announced his negotiation of a treaty with the Emperor, which allowed the Dunmer to keep most of their traditions while joining the Empire. The Temple greeted the announcement with an awkward silence, Indoril and Dres still said they would resist to the death, while Redoran, gladly took the oppertunity to not have to fight the Legion unsupported, and backed House Hlaalu's proposal of accomodation. Telvanni, seeing how the wind blew, joined Redoran and Hlaalu in their accomodation. Despite this, the Lord High Councillor of Morrowind, an Indoril, refused the treaty and refused to step down. Due to this, he was assassinated and replaced by a Hlaalu.

Elsweyr
Not much is known about how Elsweyr fared during the Tiber Wars, it is known, however, that Elsweyr had an agreement with the Aldmeri Dominion, like the Maormer and a few Reachmen.

Valenwood and the Summerset Isles
The Thalmor increased its hold on Valenwood during the founding of the Third Empire. Savage Bosmer tribes fought with the Estates along the Strid River. However, when the Empire stood united these skirmishes stopped. After the attacks stopped both sides waited on either side of the Valenwood border, awaiting the decisive battle. On the occasions that the Dominion probed the Empire's defenses, the Legion sent them back in tatters. The Colovians even took to calling them the Old Mary Dominion due to the womanly offensives of its Elven soldiers. The situation at sea, however, was another story, as the Dominion terrorized the southern waters from the Cape of the Blue Divide to the Topal Bay. Tiber Septim later used the Numidium to conqeur the Aldmeri Dominion.

Imperial force used
The recorded Imperial forces during the Tiber Wars are as follows.

Imperial Navy

 * New West Navy

Imperial Legion

 * Third Legion

Appearances
The Elder Scrolls Adventures: Redguard (During the conquest of Hammerfell)