John

1. Knights of Battle

   A trio of Arthur’s knights - Cador, Lancelot, and Owain - mentioned in Welsh legend. They were exceptionally noble and brave in combat.

   
   

2. Knights of Norway

   In the later legends Lot and Gawain are often called Knights of Norway.

   
   

3. Knights of the Franc Palais

   An order of knights founded by Perceforest, they were eventually wiped out by the Romans.

   
   

4. Knights of the Round Table

   The most chivalrous order of knights ever to have been formed. [More]

   
   

5. Knights of the Watch
   Knights of the Guard

   A group of Arthur’s knights who were brave and honorable, but were inferior to the Knights of the Round Table.

   It is first mentioned by Chrétien in Perceval. The Prose Lancelot tells us that it seated 150 knights, which may be the origin of Malory’s assertion that the Round Table sat 150. An order of a similar nature is called the Table of Errant Companions in the Post-Vulgate.

   When Gawaine comes to the Rock of Canguin, Queen Ygerne (Igraine) commences her questions about Arthur's household by asking her guest if he is one of the knights of the guard (Owen's translation) or watch (Cline's translation), who have done many valiant deeds.

   She does not mean the Round Table, for she proceeds to ask about that separately after Gawain has answered that he is not a knight of the guard; he does admit to belonging to the Round Table, calling himself "neither the best nor the worst" of that company.

   Unless the Knights of the Guard are to be equated with the Queen's Knights, I do not recall yet meeting them as a specific body anywhere else in Arthurian lore. Arthur's court must certainly have had its share of other knights, whether waiting and hoping to join the Round Table or content with lifelong service in less exalted but still essential places.