What's a cathedral chapter, you ask? It's the body of priests attached to a cathedral, who helped the bishop run the diocese. As I noted in my post on bishops, they began as the head Christian of their region (diocese). Administrative responsibilities meant that, essentially from the beginning, they needed priests to assist them.
By the ninth century, the cathedral chapter had gained a formal existence, with its own elected officers and its own property. The property attached to the cathedral church, which could be fairly substantial, was divided in two, with the bishop administering half and the cathedral chapter administering half.
The cathedral canons, the members of the cathedral chapter, each received an individual stipend, called a prebend. The number of canons was limited by the amount of prebends their share of the cathedral patrimony could generate. Although the prebend was not personal property, so the individual canon could not sell it or bequeath it, he still had it for his lifetime. Cathedral canons had individual houses grouped around the cathedral (in the "cathedral close") where they lived, supported by their prebends.
The cathedral chapter was made up of "secular" canons as they were called, in distinction to "regular" canons, those who (like cathedral canons) served a church in a body, reaching out to the broader community, but who followed a strict rule that required them to live in common, sharing their possessions, their dormitory, and their food. (Click here for more on canons regular.) Cathedral canons lived essentially pure lives, at least by the end of the eleventh century (earlier they had often been married, or at least had a live-in partner), but they did not believe in sharing.
One of the important functions of the cathedral chapter was running the cathedral school, where priests for the whole diocese would be trained. Medieval universities grew out of a few of these cathedral schools. Members of the chapter had almost always started as pupils at the cathedral school. Once ordained as priests, they might be invited to join the chapter if there was a prebend vacant, and if they came well recommended. Many cathedral chapters had virtual dynasties of uncles and nephews.
The most important officer of the cathedral chapter was the dean, elected by the canons. He stood up to the bishop if he felt that the chapter's rights and privileges were being violated. Other officers included the chancellor, responsible for the school and the archives, the provost, who oversaw the chapter's property, and the cantor, who led the singing in the cathedral--something cathedral canons did every Sunday, if not more often.
The example of the cathedral chapter suing the bishop--as indeed happened!--should dispel any lingering thought that the medieval church functioned as a monolithic unit. (Click here for more on the medieval church.)