King Anumaril was an Ayleid arch-mage and a king of Abagarlas, a city worshipping Molag Bal. He was the father of Prince Malyon and husband to Queen Palolel. During his reign the city was at war with the city of Delodiil, whose citizens worshipped Meridia. Abagarlas's forces included Molag Bal's daedra and the undead. Close to the end of the war, Anumaril has made preparations to activate the relic called Mortuum Vivicus which would drain all the life from Delodiil. This plan wasn't implemented as a group of warriors from Delodiil, with the help of Prismatic Weapon imbued with Meridia's power, managed to enter the city and stop the ritual. During the final battle of the war, the entire royal family of Abagarlas was put to the sword and the city itself was destroyed by Meridia.
He is also known as the powerful archmage who created the Staff of Towers, which is said to be able to bend and shape the time itself. It was created by him sometime during or shortly before the Alessian Slave Rebellion. The staff consisted of eight segments, each being a semblance of a Tower in its Dance. Seven fragments were later borne by White-Gold Knights to distant Fold-Places, where they were hidden. The last segment, also known as Segment One, remained with Anumaril.
After the Rebellion Anumaril fled along with other Ayleids to Valenwood. They were welcomed by the Green-Sap's Elves as long as they agreed not to dissonate the greensong and all the Heartland High Elves agreed to this except for Anumaril. He asked the Great Camoran to show him the Green-Sap. Within the great graht he found his desire – Perchance Acorn. He then attempted to convert the region into a new home for the Ayleids by plunging Segment One into the acorn. This resulted in stopping the Elden Tree from moving by turning its perchance acorn into a definite acorn, but it was not enough to convert the tree.
He is then said to use his dentition as tonal instruments, dismantle his bones and build of them a Mundus-machine that mirrored Nirn and its planets. When he had used all his substance in fangling this orrery, he placed the segment-sceptre within, hiding it between the Moons. And then he started to wait.