Board Thread:Lore Discussion/@comment-24045142-20131013053326/@comment-24044823-20131013060808

Mehrune declared war on mortals in Tamriel and was defeated by Jurgen Windcaller who used the shout called "Oblivion" with the words of Send, Trap, and Banish, Mehrune was destroyed on shattered into 5 seperate pieces. The pieces included the Head, Heart, Left eye, Right eye, and Soul. His soul was trapped in the Soul Cairn and was used to make Durnehviir the summonable dragon. His head, heart and right eye were lost all over Tamriel, however for the right eye, it was blown across skyim to a location you discover for doing the quest "Pieces Of The Past" and is used to later make Mehrune's Razor. I believe this answers your question...for the topic claims the Background of Pommel Stone of Mehrunes' Razor.