This is a "Wild Mass Guess" entry, where we pull out all the sanity stops on theorizing. The regular entry on this topic is elsewhere. Please see this programme note.
Kingdom of Heaven
Balian is a Time Lord.
After joining Richard in his failed crusade against the Saracens, Balian returned to Europe, dropped his identity as a member of the Ibelin household, and took on the name William Turner on a later date.
Reynald has tried to dye his hair/beard with henna.