Utha Uruth was the cousin of the Empress Kadaena who led the rebellion in the First Era civil war of the Shadow World history. The Uruth faction emerged victorious over the K'ta'viiri (Iruaric: "Lords of Essaence") when Utha decapitated Kadaena before the Gates of the Void with the Soulsword, specially designed of extraplanar origins to counter the immense power of her Shadowstone amulet. While the "Lord of Essaence" family was the majority of the Essaence adept aristocracy, and Uruth is apparently a surname, they are all Lords and the "Kaedanan" faction would translate as "the imperials."
When the war was over the world was badly wracked from the scale of the power unleashed, with many unhealed tears in the fabric of reality and demonic hordes running wild. Utha constructed the Eyes of Utha artifacts at the poles to seal the interdimensional rift, which were guarded by the Ahrenreth order led by his son Andraax. Utha was dead from his battle wounds shortly after these events.
Behind the Scenes
Uthex Kathiasas from the story behind The Broken Lands may be a portmanteau of "Utha Kadaena" with "Ex" and "Kadath" from the H.P. Lovecraft stories "Ex Oblivione" and "The Dream-Quest of Unknown Kadath". These are referenced in multiple I.C.E. Age locations such as The Graveyard, Shadow Valley, and Purgatory. Kadath was also addressed in "At the Mountains of Madness", "The Fungi from Yuggoth", and "The Mound", which were apparently also part of the background subtext for these areas, along with a handful of other short stories with overlapping elements. The Shadow Valley story is loosely based on the ancient Vedic myth of the brother of the serpent demon Vritra, reflecting the Shadow, being slain when the goddess Ushas (Utha) is released from a chasm.
It is not clear if the "Portal at Ruuth", one of the surviving Shadowgates, owed its name somehow to the Uruth surname. The portal was the only known way (though presumably too dangerous for mere mortals) to travel to the other side of the Wall of Darkness formed by the Eyes of Utha. Andraax traveled through it at the end of the Wars of Dominion, after being driven mad in his slaying of the Master of Malice. This is potentially relevant to The Broken Lands story as the inscription on the Dark Shrine can be plausibly translated with significance as "Master of Malice" rather than "Cruel Master."