A very stingy bishop indeed.

Traditional British port-drinking etiquette requires that the host pour for the person on his right, then pass the bottle to the person on his left (port side), and so on around the table. When your glass runs out, it's bad form to ask for more, and a thirsty drinker gets around this awkward moment by asking the person in the nearest vicinity of the bottle, "Do you know the Bishop of Norwich?"

Those who are aware of this quaint rhetorical custom will realize their error and merrily hand over the bottle. For the clueless who may answer no, the questioner gets to say, "He's an awfully nice fellow, but he never remembers to pass the port."