Rite Master Iachesis (?b - ?d)
Early leader of the Psijic Order since 1E 20, if not sooner. In the early Second Era, he welcomed an eleven-year-old boy to the order, and gave his new pupil the name Vanus Galerion. Iachesis was one of the people Galerion had to answer to when he began collecting mages from all over Summerset Isle; while Galerion's charter was granted by the King of Firsthold, it's unclear whether Galerion ever gained his mentor's support. He was a character in the popular historical fiction 2920, The Last Year of the First Era. Artaeum vanished around the time of the founding of the Mages Guild, and when it returned five hundred years later, the Psijics were led by Lore Master Celarus. They would not, or could not, offer any explanation for what happened to Iachesis.
 Jarl Idgrod Ravencrone (4E ?b - ?d)
Jarl of Morthal during the Stormcloak Rebellion. Idgrod claimed to have visions granted to her by the Nine which she relied on in her policy-making. While she was careful with her words, she was clearly a supporter of the Empire during the conflict. Her people were largely bemused by her leadership during this time of crisis. She had two children, Idgrod the Younger and Joric, with Aslfur, her husband and steward.
 Jarl Igmund (4E ?b - ?d)
Jarl of Markarth in 4E 201. His father, Hrolfdir, was killed by the Forsworn. Prior to his death, Igmund's father and the Empire established a Nord militia that included Ulfric Stormcloak in order to re-secure control of Markarth, offering the militia the freedom to worship Talos in exchange for regaining control of Markarth from the Forsworn, a promise which could not be kept once the Thalmor objected. Igmund took his father's place as Jarl of Markarth in 4E 176, following in his father's footsteps in siding with the Imperial Legion, and he continued the fight against the Forsworn for the next twenty-five years.
 Ildari Sarothril (?b - 4E ?d)
Ildari Sarothril was a Dunmer Telvanni conjurer and an apprentice of Master Neloth during the Fourth Era. She was killed during an experiment, but returned to life due to a Heart Stone which had been grafted to her. She was finally slain in 4E 201.
A member of the Council of Mages of the Mages Guild in Cyrodiil as of 3E 433. Irlav was an Imperial researcher who specialized in Ayleid studies. He was killed by necromancers while studying the Bloodworm Helm for a way to defeat Mannimarco. He was the author of Magic from the Sky.
 Isran (4E ?b - ?d)
A Redguard and Vigilant of Stendarr who left the order because it was too "soft". Isran believed, among other things, that hatred granted strength. He reformed the Dawnguard, with himself as its leader, after he spent years renovating Fort Dawnguard in the Rift. He was considered a lone wolf, and had difficulty maintaining amicable working relationships. Nevertheless, he called upon many past allies to help him fight the emerging threat of the Volkihar vampires. 
 Istlod (4E ?b - 4E ?d)
Nordic High King of Skyrim during the Fourth Era. Istlod ruled for almost twenty-five years and was considered to be instrumental in keeping the province together during the Great War. Upon his death, the moot formally named his son Torygg his successor.
 Iszara (?b - ?d)
A Redguard hero of the rebellion on the Island of Stros M'Kai in 2E 864 along with her brother Cyrus. The rebellion crushed the Imperial presence on the island, killing the provisional governor Amiel Richton, and led the way to a peace treaty between the Empire and Hammerfell that was more favorable to Hammerfell.