The reason the renaisannce writers wrote about a middle ages where the peasants and pretty much everyone else stank was because the previous century was dominated by the results of the Black Death. The plague raged for 25 years. Huge numbers of people died. 1350 - 1450 was the middle ages everyones grandparents in 1492 talked about. And that was a very different time than the 1000-1350 middle ages. Essentially Europe after 1375 was a post apocalyptic society that thought bathing had caused the problem. After 1375 the population stopped bathing. This can be seen by the change in fasion.