A nobleman, also known as a peer or simply a noble was a member of the highest stratum of european society up until the 20th century. Also exist in feminine form: noblewoman.
A nobleman was bound to his liege by a sworn oath?. The liege could be the monarch or another noble, forming a hierarchy, ususally with a king at the top.
The other stratums of feudal society were priests, burgher?s and peasant?s.