Is this Redwall (1999–2002)...?

Matthias is a mouse who lives at Redwall Abbey, a fortress under constant siege from evil rats. When the image of a great mouse-warrior begins to speak to him, he realizes that his destiny is to be the successor to a great warrior.

This is Redwall (1999–2002).

The show was based on the Redwall novels by Brian Jacques and ran for three seasons.

Matthias is a mouse who lives at Redwall Abbey, a fortress under constant siege from evil rats. When the image of a great mouse-warrior begins to speak to him, he realizes that his destiny is to be the successor to a great warrior.