In the Middle Ages there were generally no fixed family names. The Jews also only had forenames, to which they added their father's name, as in Isaak ben Abraham, ("Isaak, the son of Abraham"). For further identification they either added the name of the place from which they or their ancestors had migrated the names Fulda, Oppenheim, Fürth etc were frequent or the name of the house where they lived. If they moved to another house in the Judengasse they often took the name of the new house, so that it is often difficult to identify an individual. There are also instances of names derived from an occupation, for example Schames, the community servant who roused students for school, also called the Schulklepper in Frankfurt. Under the French Revolution and the drive for emancipation Frankfurt Jews were obliged to adopt fixed family names for registration in the roll of Israelite citizens. They had free choice of names, although fathers and sons had to adopt the same name. For the most part they retained the old house or place names.