How long did people live in the Middle Ages?
That, of course, varied according to diet, climate, location, relative wealth, etc., but the answer is surely not as long as we do now. For starters, infants and children died at a horrific rate (some say up to 1/3 of all died before the age of 5) and a significant percentage of women died in association with childbirth: 5% perhaps from the birth itself, often dying with the child, and a further 15% from childbed fever–the infections that followed a poorly managed delivery (by our standards).
Following that, if a person made it out of childhood, they could be expected to live into their middle forties, provided they maintained good health and weren’t killed in war. Both those, of course, are big ‘ifs’.
Below is the recorded birth and death date for the adult royal family of Wales and associated Marcher relations, beginning with Joanna (the daughter of King John of England) and Llywelyn Fawr (Llywelyn the Great, the Prince of Wales). Eliminating individuals who died before adulthood completely, from the dates recorded below, the mean life expectancy for women was 43.6 years, with a median of 42/43; for men, it was a mean of 48.7 and a median of 48/49.
Please be aware that these people are of the highest class of society at the time, granting them (possibly) an easier life and longer life spans. I have indicated in parentheses the cause of death when it wasn’t old age or disease.