It was during the reign of King David I that the Seton Family firmly established themselves in Scotland. Before that the family was previously known as de Lens, of the House of Boulogne and seniors of the ancient Carolingian line descended from the Emperor Charlemagne from the eldest son of Count Lambert de Lens from his first marriage.  It was Count Lambert's eldest son, the Seigneur (or Seier) de Lens who held lands in both Northumbria and Scotland.  Seier is the word from old French for Baron.

Count Lambert died when the boys were too young to administer to the important estate of Lens, and thus they followed the Flemish military contingent into England with their half-sister's husband, Duke William of Normandy, in his quest for the English crown and settled there in the north following William's success.  Count Lambert himself was the second son of his father, Eustace I of Boulogne, and brother of Eustace II, and they were lineally descended in both Eustace I’s mother and father from King Charles I, Charlemagne, Holy Roman Emperor and the first of the Carolingian Empire.

Unlike fables and stories and legends written throughout the ages, these were the actual descendants of those people.  Their story unravels with the history of Europe, going from Palestine, to Rome, to Auquitaine, to the Frankish Empire and Flanders… they migrated to England and settled in Scotland.