It comprises eight baronies and nineteen civil parishes.
The last Count of Promnitz, whose ancestor had purchased both baronies from Frederick of Bohemia in 1556, sold them in 1765 to the elector of Saxony for an annuity of 12,000 thalers (rSoo).
To this end John Locke drafted for them in 1669 the famous Fundamental Constitutions providing for the division of the province into eight counties and each county into seigniories, baronies, precincts and colonies, and the division of the land among hereditary nobles who were to grant three-fifths of it to their freemen and govern through an elaborate system of feudal courts.
Thus conceived as the holder of a great fief, the king had only the rights of suzerain over the four great baronies and the twelve minor fiefs of his kingdom.
The baronies of Bourke of Connell (1580) and Bourke of Brittas (1618), both forfeited in 1691, were bestowed on branches of the family which has also still representatives in the baronetage and landed gentry of Ireland.