The practice of land-grant became very common from the Gupta period. In the post-Gupta period the practice became rampant.
Land grant was made to civil and military personnel as also others. Those who received the land-grant emerged as a new social class Obtaining land-grants they became wealthy persons.
This will made, them important persons in the society irrespective of to which class they belonged in the varna divided society.
In short, the land grants even made the people belonging to the so-called lowest rung of the social ladder important persons in society.
The identity through birth became immaterial. The new social class can to be known by the new title such as thakur, ranak, rauth, etc.