Coat of arms, originally a personal symbol, soon became hereditary into family lines, by male descent, first in noble families but soon also in patrician families. Sigillography is the study of seals, either with coat of arms or without.
Seals are the most important source for finding the oldest representation of a coat of arms.
Belgique, Luxembourg, Pays-Bas, Allemagne, France, Recueil historique et heraldique . In ancient documents dates are often given in reference to the starting date of the reign of some king or pope. The use of the 1 january New Year Style, instead of the Easter New Year Style was decreed to be used from 1575 onwards. Genealogy is a key factor in finding the oldest form of a name, and from there, the true meaning of the name. In Belgium, the use of family names started in the larger cities arround 1250-1300.