But those who filled the grates and dusted the furniture and swept the floors stayed on, as they had stayed on before, because they seldom paid any attention to, or possibly didn’t even know, who their lord was, and in any case were too useful and knew where the brooms were kept. Lords come and go, but dust accumulates.

— Night Watch (Discworld, #29; City Watch, #6) by Terry Pratchett (Page 294)