The Overlord is the player who rules the province. While the Overlord does not own the entire province, he has feudal rights therein and can tax all of the fiefs in the province.

Bailiff ID: Who is running this fief. The owner may run it himself, but loses 30 days per season if he does so, or may assign an NPC to be the full time bailiff. In either case, the player or NPC ID number appears here. Otherwise, fief management is in "Auto Mode." This means the local officials run the fief. This is known as "auto-bailiff" mode which maintains equilibrium assuming there are no external disasters, like pillage or plague. Tax levels are raised only to a level that will provide sufficient income to keep key fief indicators (loyalty, keep, infrastructure and garrison) level. There is some surplus generated, but there is also a fair amount of graft, so you won't have much surplus from a fief run by the diligent, but larcenous, auto-bailiff.