The Ganelon Bandits are a group of bandits fought in Fire Emblem: The Blazing Blade, encountered during the early parts of Lyn's story. Lyn attempts to put them in the same group as the Taliver Bandits (the bandits that killed her tribe). However, Migal states that they capture and sell women and children, while the Taliver bandits do not distinguish who they kill.
While their leader is never mentioned it could be possible that it is Bug due to his high stats (in comparison to the other bandits), though it could be Migal, as the bandits certainly didn't seem to appreciate him dying.
The name Ganelon comes from French history. Ganelon was the brother in law of Charlemagne and step-father to Charlemagne's favorite paladin, Roland. Ganelon was a respected knight who betrayed Charlemagne to an army of Spanish Muslims, leading to the Battle of Ronceveaux Pass, the subject of the Song of Roland.