Origin of hereditary last names?

Question:

Origin of hereditary last names?

When did last names change from being simply a statement of lineage (ie:son of) or profession (baker) to herditary names that are passed down without change.

Best Answer - Chosen by Asker: In England, it began with the Norman Conquest (the Normans used inherited surnames to some extent; the Anglo-Saxons had not), but the process was slow. Although they were relatively common in the 13th century, and well-established in some cases by the 14th, inherited surnames did not become completely normal in England until the 16th century.

The key factor seems to have been lawyers. They handled land transfers, records of military service, notice of creditors and debitors, as well as criminal and civil court cases. All of this required precise identification. Occupational and locative bynames can change if a person switchs jobs or moves; physical bynames can change as a person ages; patronymic bynames are better, but in area (for example) where the name John is popular, the possibility of having more than one "John filius John" (John Johnson) in increased. Inherited surnames solve these problems for the most part.