What was the life expectancy of a Medieval European monarch?

This answer is intended to complement those of Denis de Bernardy and Luís Henrique

When compared over a similar time period, Danish, French and Leonese monarchs had shorter lives than their English counterparts who averaged 48.2 years (according to the data presented by Luís Henrique, calculated starting with Edward the Martyr to match the range of Denmark). The data here is from the List of Monarchs of Denmark, France and Leon plus various other Wikipedia pages.

DENMARK

From Sweyn I (b.960) to Christian I (d.1481) average 42.4 years (31 monarchs)

Note: This is excluding 4 monarchs whose dates of birth are unknown. Information on monarchs before 986 is too unreliable to be of much use.

The calculations for Danish medieval monarchs can be found here. At least 9 of the 31 on the list were killed or died from wounds in battle.

The Danish king who lived the longest was Eric VII of Pomerania (died 1459, aged between 76 and 78. The youngest was Olaf II who died 'unexpectedly' at the age of 16 in 1387.

FRANCE

From Clovis I (b. circa 466) to Louis XI (d. 1483) average 40.4 years (64 monarchs)

This excludes the disputed reign of the English Lancastrian King Henry VI. Kings up to Louis VII (died 1180) were Kings of the Franks.

None of the French kings in this time period had particularly long lives but more than half (12 of them) passed the age of 50. John the Posthumous had the shortest life: born 6 months after his father Louis X died, John lived just 5 days.

An analysis of the average age at death of French kings by House shows a clear pattern.

• Merovingian (486 – 751) average 36 years (27 monarchs)
• Carolingian (751 – 987) average 41 years (16 monarchs)
• Capet (987 – 1328) average 44 years (15 monarchs)
• Valois (1328 – 1483) average 52 years (6 monarchs)

Note: Included in the Carolingians are two Robertian kings and one Bosonid king.

The calculations for French medieval monarchs can be found here.

Perhaps somewhat unexpectedly, the two oldest medieval monarchs of France were both Kings of the Franks and pre-900 AD: Charlemagne (aged 71, died in 814) and the Merovigian king Chlothar I (aged about 64, died in 561).

Although the Capetian monarchs averaged 3 more years than the Carolingian ones, infant mortality was the same for the 9th century Carolingians (45% before the age of 20) as it was for the 13th century Capetians.

COMPARING THE ENGLISH, DANISH, FRENCH AND LEONESE MONARCHIES

Only by reducing the time periods for England and France to match that of Denmark can we make a meaningful comparison between the three monarchies. I've also added Leonese monarchs. (Note: the data for England is taken from the link provided by Luís Henrique)

England - Edward the Martyr [b.962] to Edward IV [d. 1483] 48.2 years

France - Louis V [b.966] to Louis XI [d.1483] 45.3 years

Leon - Ramiro III [b.961] to Henry IV [d.1474] 42.7 years

Denmark - Sweyn I [b.960] to Christian I [d.1481] 42.4 years

For the adult royal family of Wales and associated Marcher relations (earliest born was 1168, last to die was 1333), Sarah Woodbury has calculated a life expectancy of 48.7 for men and 43.6 for women (but she doesn't say what age she starts with for adults).

COMPARING MONARCHS WITH THE GENERAL POPULATION

As already noted elsewhere on this site (see the link provided by the OP), life expectancy for a boy reaching the age of 20 in the 13th century medieval Britain was around 45. If we compare this to monarchs who were alive during at least part of the 12th, 13th & 14th centuries (using only the 13th century gives too small a sample), we get the following averages (Note: the data for England is taken from the link provided by Luís Henrique):

England - Henry I [d.1135] to Henry V [b.1386] 53.4 years (13 monarchs)

France - Philip I [d.1108] to Charles VI [b.1368] 46.1 years (15 monarchs)

Leon - Alfonso VI [d.1109] to Henry III [b. 1379] 45 years (14 monarchs)

Denmark - Eric I [d.1103] to Eric VII [b.1381/2] 44.3 years (21 monarchs)

Note: John I (France) and Olaf II (Denmark) were excluded as they did not reach the age of 20. Sancha (Leon, b.1191/2) was excluded as her date of death is uncertain.

Although the samples are smaller than one would like to be fully confident of the figures, one can tentatively conclude (for 13th century England at least, given the 8-year difference between monarchs and the general population), that being a monarch meant you lived longer despite the undoubtedly higher murder rate.

Jean-Pierre Deregnaucourt, in La mort au Moyen Age: les hommes et la mort à la fin du Moyen Age, states that the life expectancy data for 13th century England given in Russel's British Medieval Population (p. 186) is applicable to France and Europe in general (this is also stated in one of Woodbury's aricles). This gives 31 as the life expectancy at birth, so it does not seem unreasonable to assume that life expectancy at 20 (45 years) was not much different in France either. For the 14th century, though, he states that the Hundred Years War had a greater effect on mortality rates in France than in England.

For England, including the Kings of Wessex from Æthelberht on (the first I could find a birthdate for), and the Kings of England up to Edward IV, whose reigns extends to 1483 (and consequently into Modern Ages, if we take the usual date of 1453 - the fall of Constantinople - as the end of the Middle Ages), I found the average age of death of monarchs to be 44 years. (see here for calculation details)

I have included Mathilda and Edgar Ætheling in the calculation, but not Louis VIII of France (because he would be included in a calculation for France). As for many of the earlier kings there is no certain date of birth, I calculated age of death by merely subtracting year of birth from year of death, disconsidering months and days.

I don't know if England is representative of the whole of Europe for that time (if you don't think so, the calculation can be extended to other countries, as far as we agree on what is a country or a king). But the conclusion would surprisingly seem to be that the life expectation of European Mediaeval kings was shorter than that of the population in general. Murder, war, and accidents with weapons would probably responsible for that - at least 8, and perhaps as much as 12, out of 37 English mediaeval kings - between 20% and 33% - died a violent death, not counting 3 kings who died of disease quite certainly caused by the unsanitary conditions of battle fields.

Edward III was king during the Black Death, and survived it.

For Portugal, I found an average of 54 years and a fifth. I could find data starting with Henrique, Count of Portugal. So the count includes Henrique and Teresa, the last counts, then all kings from Afonso I Henriques up to Afonso V, whose reign lasted to 1481, so already into the Modern Age.

It seems none of these princes were murdered or died in war (which is curious, because they certainly warred a lot). Only three of them (Afonso II, Sancho II, and Fernando I) died before 40 years. Perhaps their life expectancy is what we should expect of noble families of the late Middle Ages when violent circumstances are excluded?

Afonso IV was king during the Black Death, and survived it.

(Partial answer.) I think three points are worth noting about life expectancy before comparing today's figures with those in the past:

1. Life expectancy at birth isn't such a great data point, when half or more newborns don't make it to adulthood or when women frequently die while giving birth. Both of the latter issues were common, for the rich and poor alike, until well into the industrial revolution (end of the 19th), so it's more interesting to look at life expectancy after childhood.

2. There were regular pandemics at the time. Diseases occasionally affect the lower classes more than the upper ones to some degree or vice versa, and the Plague may have affected the former a tiny bit more than the latter (who could afford to flee) - but this is a far cry from the degree by which Cholera was a poor's disease first and foremost in the 19th. Other major life shorteners of the time, like Smallpox, similarly were equal opportunity pests.

3. Famines were a thing in the past. They were a major killer that disproportionally affected the lower classes.

With this in mind:

1. Life expectancy upon reaching adulthood was shorter in the past than it is today (e.g. you'd live up to age 64 or so on average in late Medieval England if you made it to adulthood).

2. Yes, a nobleman or a monarch, who enjoyed slightly better hygiene than the commoner, and more/better food, would have lived somewhat longer. Primarily, I'd put forward, because the upper classes had food to begin with during famines.

Yet, insofar as I understood, the difference between the two was not that significant in practice. Diseases afflicted both. Famines disproportionally afflicted the poor, but methinks comparing the life expectancy of the wealthy elite who can afford food during a harvest failure with that of the poor who cannot is a bit like comparing apples to oranges. Similarly, comparing life expectancy of anyone with that of those who lived through the Black Death isn't fair. If you adjust for famines and diseases (and child birth, in the case of women), life expectancy between the two groups then probably wasn't so different, or for that matter not so different from what it is today.

I'd add in passing that, even today, a new pandemic like the Spanish flu could potentially wipe out swaths of people, making little if any distinction between the poor and the rich. The major changes between the Middle Ages and now revolve around improved sanitation (eliminating filth-related diseases), hygiene (ensuring women and babies survive birth), vaccines for diseases that were prevalent in the past (ensuring most children make it to adulthood), and of course antibiotics (ensuring sick children and adults survive diseases or surgical acts that could have been fatal a century ago).