Donald Ban was the second known son of Duncan, and the younger brother of Canmore. Despite his presence in the backstory of the "City of Stone" flashback scenes, Donald Ban did not appear in any episode of Gargoyles.
Following Macbeth's ascension to the throne of Scotland in 1040, Donald Ban was taken to Ireland for his own safety.  Sometime later he returned to Scotland, and he succeeded his brother to the throne of Scotland, becoming Donald III.
- Donald Ban at Wikipedia, the Free Encyclopedia