Petty nobility
Petty nobility is dated at least back to 13th century and was formed by Nobles/Knights around their strategic interests. The idea was more capable peasants with leader roles in local community that were given tax exemption for taking care of services like guard duties of local strongholds.
Cavalry service was not required from these petty noble families.
Later on many of these petty noble families gained full nobility ranking.
Finnish Vehkalahti is particularly noted in literature for as having been an example of such petty nobility (Finnish: knaappiaateli).
Also in Georgia the aznauri became defined as dependent nobles, as a result of stratification within the feudal aristocracy of Georgia.