Bachelors at Oxford studied the arts of grammar, rhetoric, and logic, and then music, arithmetic, geometry, and astronomy, until they mastered their discipline and therefore were authorized to teach it. Teaching would then provide an income sufficient to support a wife. The master of arts was analogous to the master craftsman of a guild. From 1190, the civil law was studied, and shortly thereafter, canon law. Later came the study of medicine. The use of paper supplemented the use of parchment for writing. Irregular edged paper was made from linen, cotton, straw, and/or wood beaten to a pulp and then spread out over a wire mesh to dry. In this era, the English national race and character was formed. Stories of good King Arthur were popular and set ideals for behavior and justice in an otherwise barbaric age where force was supreme. His last battle in which he lay wounded and told a kinsman to rule in his place and uphold his laws was written in poem ("Layamon's Brut"). Romantic stories were written and read in English. The only people distinguishable as Anglo-Saxon by their look and speech were manor villeins who worked the farm land, who composed over half the population. Intermarriage had destroyed any distinction of Normans by look or speech alone. Although the villeins could not buy their freedom or be freed by their lord, they became less numerous because of the preference of landholders for tenants motivated to perform work by potential loss of tenure. Also, the Crown's protection of all its subjects in criminal matters blurred the distinction between free and unfree men. The boroughs were dominated by lords of local manors, who usually had a house in the borough. Similarly, burgesses usually had farmland outside the borough. Many boroughs were granted the right to have a common seal for the common business of the town. Each borough was represented by twelve reputable burgesses. Each vill was represented by a reeve and four reputable men. Certain towns sponsored great seasonal fairs for special goods, such as cloth. Less than 5% of the population lived in towns. Some windmills were used. London guilds of craftsmen such as weavers, fullers, bakers, loriners (makers of bit, spurs, and metal mountings of bridles and saddles), cordwainers (makers of leather goods such as shoes), pepperers, and goldsmiths were licensed by the King, for which they paid him a yearly fee. There were also five Bridge Guilds (probably raising money for the future construction of London Bridge in stone) and St. Lazarus' Guild. The wealthy guilds, which included the goldsmiths, the pepperers, and three bridge guilds had landholding members who had been thegnes or knights and now became a class of royal officials: the King's minters, his chamberlain, his takers of wines, his collectors of taxes.