The Atmorans, ancestors of Nords, and in turn Imperials and Bretons, made a home for themselves in Sarthaal during the Merethic Era. After many years of thriving in this new land, which the Atmorans called Mereth due to the concentration of elves and natural magical forces, the Snow Elves invaded Sarthaal to destroy to rapidly growing city. The Atmorans themselves were unsure of their motive, as they traded with the Snow Elves and befriended them. It is possible that they were after the Eye of Magnus, but I'm unsure if it was their at this time, as the Atmorans would surely leave some written record of such a discovery. Soon, Ysgramor returned with an army known as the 500 companions, and waged a bloody war which drove Snow Elves into the arms of the dwarves to avoid extinction, which ultimately lead to their devolution into modern falmer.