I've been getting alot of questions on where people fit on the above chart, so here is a brief explanation of the classes, taken from Garnett and Syn's Book of Customs. Hope this clears things up!

Ealdormen (Alderman) - County officials, rulers, the upper class. Ealdormen hold land and collect taxes from the Thegns, as well as hold official troops.

Thegns (Thanes) - Below Ealdormen, but still important men and landowners. They watch over the land, and can raise the fyrd. Some possess their own fortifications and personal troops.

Knights - The warrior class sworn to protect the royalty and Nharati. Knights do, or at least can, usually possess their own land. There are exceptions.

Ceorls (Corrals) - Free men and women of the lowest rank. The men are required to take up arms when the fyrd is raised, but they are free to endeavor in whatever enterprise they wish.

Serfs - Peasants who are pressed into a caste system according to the thegns.

Within the upper ranks, women do not hold the rank by their own right. It is only by virtue of family position and marriage that a woman may be considered part of the Ealdormen or Thegn classes, and even then she does not participate in the governing of Nharati.

Lesser foreign nobles are referred to as 'earl'.

Correction: Knights DO, or at least CAN, usually possess their own land. There are exceptions.

Disinherited knights are basically the feudal answer to the samurai's ronin. They are wandering knights, unless they can attach themselves to an important household. A good variety of the capital's knights are likely to be disinherited men who wish to garner favour with the royalty in return for land.