Alyeids, one of the most ancient races of Tamriel, they're also known as the "Ancient Ones", they were the first race to make a vast empire, they lived in a more "tribal society" and were the founders of the Imperial City, they noted the fortress as "white gold tower" at the time period. They spoke Cyrodiilic, and is an offshoot of the Aldmeris. Many Alyeid Ruins can be found in Cyrodiil, these ruins are filled with quiet an adventure, bandits, undead often control the ruins. The Alyeids had a firm grasp of magic, as many of their ruins contain stones filled with magicka essences. The Alyeids were descendants of the Aldmeri, they emigrated to Cyrodiil (From Summerset Isles). At a point in the Alyeids conquest, they owned nearly all of Cyrodiil, and enslaved Nordic, and Cyrodiilic peoples but were later overthrown by Slave-Queen Alessia.
Ayleid culture lingered in the city states that survived as client kingdoms of Alessian Cyrodiil, but the elven population of Cyrodiil was finally driven into exile (often to Valenwood) by the intolerance of the Alessian Order. Some say that Alyeid populations still linger into the depths of Cyrodiil's forests, but this is unclear, the recent reported sightings are more than 1000 years old, they have a gold-brown complexion, as lore says "they are darker than a Altmer, but lighter than a Dunmer" All of these races evolved from the Aldmer, those who went to morrowind evolved into the Dunmer, those who stayed in Summerset Isles became the Altmer, those who went to Cyrodiil became the Alyeids.