|“||Choose your immortality wisely, whether it be the treasure you amass, or the family who succeed you.||”|
|— Advice to a Patriarch, Baron Bresling|
Baron Bresling was a Baron in the Thief World. He is the only 'cannon' Baron to have been named in the Thief lexicon.
It is possible that he was the current Baron at the time of Thief: Deadly Shadows, or a Past Baron.
It is unknown which 'Patriarch', Bresling talked to. It could be inferred to be the Rutherford family or a king above him (very little of the World beyond the City has been seen or heard of).