In our campaign, I'm going to make a French high ranking knight of some sort, and I wanted to ask what kind of noble title which would be suitable. I don't know too much about French nobility in the middle ages, but I'm thinking a character with his own castle, a couple of villages or towns to rule. I'm also trying to place him in Champaigne or French Burgundy, perhaps near Avallon. What rank of noble would be suitable for a character with some amount of power, but enough freedom to be playable, going on adventures, crusades or what have you? I'm thinking of a Baron, but I'm not even sure what that title involves. Can someone enlighten me and give me some ideas and inspiration for this French noble?
One of my main sources of inspiration is the Godfrey, Baron of Ibelin from the movie Kingdom of Heaven (character played by Liam Neeson).
In Champagne and Burgundy many landed nobles were not Counts (which was already quite high a title at the time, for instance Count of Burgundy, Toulouse or Brittany) or Baron (which is more English or German than French).
Often a single noble held several landed titles, and control over those lands. They would use the highest of these, but practically speaking the power was additive. So a mere "baron" could have enough different holdings to rival Counts, etc.
No, Sire is also for a non-titled (but landed) noble, like were most of the French nobles. Like a "default" title when having no more prestigious one.
Some were even quite renown, such as the "Sire de Coucy", who made it his motto: "Je ne suis roy, ne prince, ne comte aussy. Je suis le sire de Coucy", "I am neither king nor prince nor count. I am the Sir of Coucy".
I'm not sure "Chevalier" meant as much in the middle ages as during the modern period (during which it was integrated in the standardized hierarchy of titles from emperor to squire), but it was certainly the lowest common denominator between all nobles. Maybe I'm not quite clear, that I want to say in that in French middle ages I'm not sure the "Chevalier de XXX" title was really used as a title, even if the noble was indeed a knight, e.g. the distinction between "a knight" and "the Knight of XXX".
It's actually a very interesting question you asked as the "picture" of the middle-ages nobility is quite muddy and lack primary sources.
Often what is presented is tainted by late medieval and Renaissance information. Also there is no consistency as customs and laws would change from one region to another.
Another confusing issue rises from the fact that feudal nobility was mostly linked to military service, but not exclusively, which bring a further distinction between nobles who could have an armed force and those who were mostly land administrator. Also keep in mind that a Seigneur could also be an ecclesiastic institution, link a monastery!
What was probably the lowest rung of the feudal ladder was the "Seigneur" and when you said their name you would call them Sieur (like in Sieur de Joinville). There seemed to be "land lords", who would administer economically one (or rarely a few) parishes. They couldn't raised armed men. This privilege was reserved for the military nobility, knights and squires, that would get once again a parish or another source of income (like a toll) and raise taxes to maintain armed men. These nobles would usually have a fortified residency on their land, sometimes nothing more then a fort-house.
Above them you would find "châtellenies", which was probably the smallest administrative unit of the time and would regroup around 10 parishes (often less, but sometimes up to 40). These nobles were still called Seigneur, lived in a castle, had economical and judicial powers and would of course maintain a small force of armed troupes. They would have a number of Seigneur under them, some hereditary and some named by them. Sometimes they would sell "land lord" titles to introduce successful merchants or farmers to the nobility. This "title" wasn't hereditary: the "Castellan" was named by a higher authority and would stay in this post for a certain number of years.
For your character, I would recommend a simple military Seigneur, a Sieur de ... with a small castle and a few parishes to administer.
Here is a link to a dictionary with names of Seigneuries in France (in French, but it's easy manage, each entry giving the name of the place, a letter for the type (Seigneurie, Comté) the name of the family owner and the date they took possession). If you're looking for something authentic!
I don't think you can place a "châtellenie" and a "seigneurie" in the same hierarchy. In many case they will be confounded as a châtellenie simply refers to the piece of land over which the castle chief (a noble or its representative) has rights and a seigneurie is the piece of land a seigneur has rights over, whether he has a castle or not. In both cases the seigneur could be a landed noble or an ecclesiastic institution (monastery, bishopric, etc.), they both are basic units of land organisation.
Moreover multiple seigneurs could have different rights on the same piece of land, one having the right of high justice and another one the right of low justice, one having the right to collect tolls on the local road and another one the right to collect taxes from the peasants, etc.
For seigneur, sire and sieur, they are the same word, from different times in the middle ages and different regions in France. I think sieur is the one which sounds the most medieval in French (the least used now) but I know for sure that seigneur and sire were used in medieval times as well.