What invention advanced life in the Middle Ages the most?
Life expectancy throughout human history has been heavily skewed by two factors, against which, during the Middle Ages, humans made little headway. The foremost was the fact that many newborn children did not make it past the first hurdle and died in the first five years of life. A combination of malnutrition and infections would have accounted for a large number of these deaths and the first born also had a fair chance that he or she would be motherless before growing into adolescence. And the reason for the large number of motherless children was that women died in childbirth in large numbers. In fact, safe childbirth was not to happen until after the famous doctor, Oliver Wendell Holmes persuaded doctors to wash their hands between delivering babies (and that was not until after 1843), and thereby reduce the infection rates that they unwittingly transferred to their patients called puerperal fever. So the to your question is the wealthy develop sanitation primarily for hygiene reaso
