Marcomir of the Franks, born about 360, was descended from the Salian Franks who had in 355 left the Salland on the Ijesel (the Ijssel or Yssel river ancient Sala - a navigable river in the Netherlands near the north mouth of the Rhine). The Salian Franks migrated to the Roman fortification in the land of the Batavians. They occupied the towns known as Xanten, Cologne and Bonn.