doomsday book
After William the conquerer's invasion of England in 1066, after defeating an army fresh out of another invasion (The last time England was successfully invaded in the last 1000 years), he set about discovering the value of his assests. Every person, serf, baron, knight or clergy was recorded in what could be called a form of early census. Land, building, livestock and other materiality were counted, so as to give a total value for a village. The average price of a village was then £8 ($14), today, it would be about ten million that amount at the very least.
The name came from the surveyors, who claimed finding out the information was like doomsday.