In 1015, Werner laid the first stone of a cathedral on the present site of Notre-Dame de Strasbourg.
According to Eduard Hlawitschka, this Werner and his brothers Rudolph I and Radbot of Klettgau were the first members of the Habsburg family. They were sons of Lanzelin, count of Altenbourg, and of Lutgart, countess of Nellenbourg (daughter of Eberhard, count of Thurgau).
He died of fever, on the banks of the Bosphorus. He had been on his way to Constantinople.