Estates of the realm

The Estates of the realm were the broad orders of social rank and hierarchy in Europe from the 6th century to the 17th century (up until the 18th century in the case of France under the Ancien Regime) that divided the population into a series of estates, although how many depended on the country and era.
Examples.
For example, in pre-revolutionary France, the three estates were 
Some people refer to journalism as the Fourth Estate.