The Tamriel Guard are the law-enforcing guards found in most settlements across Tamriel. They are responsible for collecting gold from players with bounties, or killing them if they refuse. Guards are also responsible for general security and will attack any hostile creatures or NPCs that pass near them.
Tarnished is the name given to those unfortunate citizens of Clockwork who have been cast out from society, unable to find a role and have been essentially abandoned by the Clockwork Apostles, although they are provided the basic essentials of clothing, food, and water. Tarnished within the Brass Fortress live in Slag Town and run the outlaws refuge there.
The Tenarr Zalviit (Ta'agra for 'Night Stalkers') are an ancient Khajiit clan of vampires that reside in the Tenarr Zalviit Ossuary, a burial crypt deep in the Weeping Scar. They have been around since before the Thrassian Plague.
The Ternion Monks are an old order of peaceful Nord monks settled in Mistwatch. They are one of the few who still worship the Three Old Gods. When High King Jorunn was poisoned, they were the one, with the help of an Argonian dreamwalker, who found a way to save him.
The Thalmor are the political and diplomatic representatives of both the Summerset Isles and the Aldmeri Dominion. They are responsible for almost every aspect of the Dominion on the mainland, and have the authority to do whatever is necessary to win the war.
The Tharn Family is a powerful Imperial family allied with the Empire.
The Thieves Guild is a criminal organization consisting of rogues and thieves found all over Tamriel. It is based in the city of Abah's Landing, found in Hew's Bane on the southern coast of Hammerfell.
The Thorn Legion are both the Vampire clan and army personally loyal to Lady Thorn. Recently, their allegiance with the reborn Gray Host has become known as well as plans to march on Western Skyrim from their home Castle Thorn.
The Thornfang Pack are a pack of werewolves who have recently taken over Archon's Grove in Summerset. Their leader decided on this move as the resident Altmer were unused to dealing with werewolves and the lack of competition meant they are free to rebuild their numbers after several losses against rival packs. Recently, they have begun the risky business of kidnapping travelers and turning them in a bid to fortify the pack.
The Thornroot Clan are Reachfolk living around 2E 582. When the Gray Host came along, they welcomed and later betrayed the Hillhunter Clan, using captured clan members to create Briarhearts as protection from the Gray Host. They are led by a hagraven named Matron Grygarsnit.
The Thorns are a group of Imperial bandits based out of Thorn Lodge, near the city of Cheydinhal. Like most of the bandit gangs in Cyrodiil, the Thorns are a group of looters who formed after the Alliance War broke out. They have been a particular nuisance to the rebel movement that's attempting to free Cheydinhal from Legion control.
A group of Treasure Hunters have been hired by Quintus Verres to excavate the Dwemer ruin of Volenfell. Guided by the notes of Verres' spurned wife, Tharayya, they search for the Guardian's Eye, a powerful Dwemer artifact sought after by the Mages Guild and famed archaeologists alike.
The Triad is the name for the alliance of Clavicus Vile, Mephala, and Nocturnal. The three Princes have formed a triad to wage war against their fellow Daedric Princes and reshape Nirn in their own image. As such, this group serves as the main source of conflict for the Daedric War storyline.
The Triad is able to act as it does because these three Princes were not present at the signing of The Coldharbour Compact, an agreement with Sotha Sil forbidding them from directly interfering with Tamriel.
In the Summerset chapter, the cult of followers this triad has attracted is referred to as the Court of Bedlam. These groups, along with a Sea Sload alliance called the Abyssal Cabal, attempt to invade Summerset and Artaeum towards the ultimate goal of unlimited power and remaking Nirn in their image.
The Tumnosh Clan are an orc clan living and working in Graystone Quarry. The Dwarven machines in the mine malfunctioned and started attacking the workers, prompting the chief to attempt a rescue mission.
The Twilight Cantors are a Khajiiti group of musicians who use a magical form of singing. When dro-m'Athra arrive in Tamriel, the Cantors are called to sing them back to the void. They otherwise spend most days sleeping and living a life of wine and prayer―full of dozing and bathing and joyful music.