In the Abbey of Redwall there is a tapestry that depicts Martin The Warrior of Redwall vanquishing the Abbey's enemies. Over the course of the series Martin's image seems to shift position. I believe it starts out in the bottom middle, but in later books it is describes as being (I think) in the botttom center.
Addendum: In Redwall (pub. Ace paperback 1998) pg. 52, bottom right corner. In Triss (pub. Philomel 2002) pg. 69, center. In Loamhedge (pub. Firebrand 2005) center.
Why is this?