Social Class
The society of 1007 is rigidly class-based, especially in Christendom. The modern idea that any child might grow up to be anything is entirely alien to this society. In this society, the position a person occupies is the one into which he was born.
The most fundamental class division is free vs. unfree. The vast majority of people are unfree — they were born unfree, their children will be unfree, and they will almost certainly never have the option to be free. In pagan lands, thralls have a bit more flexibility than their Christian counterparts. Though thralldom is also hereditary, a thrall is more likely to gain his freedom than a serf.
Even among the unfree, there are strict classes. Serfs come it two categories — villeins and cottars. Villeins have the tenancy rights to agricultural land, and cottars do not. As a result, villeins are much better off than cottars. Because tenancy is hereditary, these class lines do not change from generation to generation — the children of a cottar are doomed to be cottars themselves. The most prosperous villeins (those with the most land) are chosen for special offices, such as miller or reeve.
Among the free classes, the line demarcating the upper class is very strong. Knights, nobility, and royalty are their own echelon. A freeman who is not born noble will probably never become noble (though it is theoretically possible for a freeman to be knighted). A nobleman will always remain in the nobility, simply because of the circumstances of his birth. In pagan lands, this is again a bit more flexible; there are certain (low-level) noble titles that are not hereditary — instead, the king can grant them to any freeman.
Among the free who are not in the upper class, there are class divisions as well. These are wealth-based, and more familiar to a modern player, but they are still fairly rigid. A few freeman own so much land that they do not have to work it themselves. These are gentlemen, and likely are from noble families, even if they are commoners themselves. Gentlemen outrank yeomen, who are free farmers who own their own land, and work it themselves. Yeomen outrank tenant farmers, who are free, but own no land, and rely on tenancy like the serfs. Theoretically, a yeoman or tenant farmer can leave the land to do something else, but most never will. They are free by law, but still confined to their social class by economic necessity.
In towns, everyone is free — the towns form a middle class. Still, there are strict demarcations of class within towns. Some men must work as laborers, and they form the bottom rung. Other men are guild members, and therefore can theoretically advance in society by becoming masters. In practice, the rank of master is doled out rarely, and the children of current masters are more likely to be given it than others. In addition, some guilds are more prosperous and prestigious than others. A young man's career is not selected by him — it is determined by what apprenticeship his family can negotiate for him. The son of a member of a poor guild (or a laborer) is not going to be apprenticed to a rich guild.
The Christian church is theoretically outside of the class structure, since all of the clergy have forsworn their previous, secular life. In practice, however, the church is just as dominated by class structure as the outside world. Sons of important fathers are more likely to gain positions of power within the church. Sons of poor fathers are likely to remain of low rank once they take vows.