According to legend, the Holy Roman Emperor Frederick II, who was intelligent (spoke six languages) and influential, also purportedly used cold-blooded methods to further his "scientific" inquiries. According to the Wikipedia entry:

[Frederick] was also alleged to have carried out a number of experiments on people. These experiments were recorded by the monk Salimbene di Adam (who despised Frederick) in his Chronicles. Amongst the experiments included shutting a prisoner up in a cask to see if the soul could be observed escaping though a hole in the cask when the prisoner died; feeding two prisoners, sending one out to hunt and the other to bed and then have them disemboweled to see which had digested their meal better; imprisoning children without any contact to see if they would develop a natural language.

I've read this elsewhere long ago, and as there isn't too much information about Frederick, I'm wondering if anyone can point to a definitive source. Certainly Salimbene di Adam might have had an axe to grind, but the consistency of the accounts makes them seem believable and, given the character of Frederick (his belief in reason, his winning of Jerusalem by treaty rather than by war), which points to an unconventional mind that was unhobbled by conventional restraints.

Can anyone clarify this issue? Was Frederick a real monster or someone who had been given the 13th century version of a swift-boating by the Church he defied?

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    If you're going to question a narrative, please provide a reason why.. You've cited one source, and then invoked Godwin's law. Is there a reason you doubt the source/narrative? If you're just looking to confirm or deny the existing narrative, the hyperbolic references to Nazi's undermine your question.
    – MCW
    Commented Jan 14, 2016 at 13:14
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    @MarkC.Wallace: The narrative is already in question. That second sentence in the Wikipedia quote alludes to it, and every time I have encountered the reference it has been cast into doubt even as it is being put forth. Now, what exactly is hyperbolic about my reference (singular) to a single Nazi? If the "experiments" Frederick had carried out were fairly recorded, they would certainly be tantamount to the kind of soulless cruelty Mengele practiced, so any reference to such deeds would be facts, not exaggerations, and drawing a comparison between the two figures would not be invidious at all.
    – Robusto
    Commented Jan 14, 2016 at 14:12
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    @Mark the reference to Mengele is totally justified as a characterisation of these allegations.
    – Ne Mo
    Commented May 13, 2016 at 10:40
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    considering the various nasty execution methods for criminals in medieval times, these are mild experiments. They do not necessary imply long, excruciatingly painful deaths, the casket one might even use a prisoner that was dying for any reason, including other torture method. Any prisoner in the death row would gladly choose to participate in these experiments instead, e.g., of going to the wheel. About the children, it is easy to critique when you have knowledge enough to know the outcome.
    – Luiz
    Commented Feb 18, 2020 at 16:47
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    But he was not a saint, Daniel-Rops even tells that he raped his wife on wedding night (marriage contract was signed when she was 11 years-old with the understanding that the marriage would not be consummated for a few years) AND her cousin who was sent with her to make company to the child-bride. I do not think he would have any qualms about experimenting with death row prisoners or orphaned peasant children
    – Luiz
    Commented Feb 18, 2020 at 16:56

4 Answers 4


I found a number of various sources that had different versions of the examples you provided from Wikipedia. For example, one story claimed that he put a number of prisoners in an airtight room and then once he was certain they had suffocated, he had the door opened very slowly so that he could observe whether or not their souls could be seen escaping the room. With the experiment on infant children, each example I found stated that the mothers were instructed to not speak or show any form of expression towards the children so that he could see if they would develop natural speech on their own. There were different views on whether the experiment involved two, three, or possibly more children, but all sources agreed that each of the children died before developing any speech patterns.

Perhaps the best answer to this came from a Lecture in Medieval History:

Not all of his scientific bent was exercised [in] such unacceptionable ways; he often engaged in bizarre physical experiments. With Frederick one never knows whether what one reads in sources from the period is an honest attempt to tell the truth about him, a fantastic bit of gossip, or a downright lie.

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    Interesting. The man sounds like a very dangerous figure -- somewhat intelligent, wielding huge power, yet so evil. Still, one wonders whether things were exaggerated somewhat here.
    – Noldorin
    Commented Oct 28, 2011 at 16:35

Frederick II was not a monster. One must consider when he lived, for one. They had NO idea that keeping children in that way would mess them up psychologically, as it surely would, if they even lived, which they didn't, and they didn't know it would kill them, either.

Prisoners were deemed at the time to have given their lives to the State. ANYTHING could be done to them and often was.

My point is NOT to say that what Frederick did was totally cool so get over it. But it was not unusual given the time in which he lived. Look what was going on in other parts of the world at the the time. Execution by boiling, or flaying alive, or Heaven only knows what else.

It should also be noted that Frederick was FAR in advance of his time in many areas as well. He was the first European monarch to forbid Trial by Ordeal, for example. He also created the first State University, the University of Naples, now called the University of Naples Frederick II. It was the first university in Europe NOT run by the Church (thank God).

He was the first to create the concept of a centralised nation-state, which he did for the Kingdom of Sicily. The Liber Augustalis, also called the Constitutions of Melfi, remained the Basic Laws in Sicily all the way down to about 1818.

If those stories are true, was it cruel of him? Perhaps. But given the standards of the time, not worse than any monarch. He was also HIGHLY tolerant of Muslims and Jews in his lands. Under Frederick, either group was able to pretty much live as they wished, without fear of the State, as long as they weren't loud about it. There were no pogroms, no big men with swords knocking on the doors at night during his reign. Jews and Muslims also flourished at his court as scientists and translators of Aristotle and other Greek, Arabic, and even Hebrew learned persons.

Frederick himself was no slouch. In addition to speaking German, Italian, Latin, French, Arabic, and one other tongue (I don't recall which) he was also an avid sportsman who wrote a well received book called De Arte Venandi cum Avibus, The Art of Hunting with Birds, commonly known in English as the Art of Falconry. In it, he describes the nature and care of birds generally and birds of prey in particular, and how to hunt with the latter. His book is still in print. He challenges Aristotle frequently, and was proven right in the 19th century by bird specialists. The writer of this answer is lucky enough to own a copy.

The man was NOT perfect. Nor would he have claimed to have been. If the story about the children IS true, I expect he probably regretted their deaths, since no one knew that would occur. But these stories have circulated for CENTURIES! Are they true? Who can know at this point? There is no proof, and never will be.

Frederick was a man who inspired passions in everybody who dealt with him. Either you LOVED him or you HATED him. Very rarely were your views of him mild. Its just the way things were with him. You readers can tell I am rather fond of the man. But even I admit he could probably be quite unpleasant if you got on his bad side. We all know I mean the List where the Human Waste resides. And by unpleasant, I think we can all surmise my meaning.

Be ready for the book when it comes out. Thanks. The info I gave here is stuff you can find with just some basic research. My book will expand on that and make some very interesting claims that you should all enjoy.

EDIT: It should be noted that, although Frederick DID create the concept of the centralised nation-state, if you will, in the Kingdom of Sicily, he, quite sadly, did EXACTLY THE OPPOSITE in Germany. Frederick had spent his entire life in Palermo growing up. There he had receieved a cosmopolitan education at the hands of a multiplicity of tutors both Christian and not, and had breathed in the scent of the crossroads of Europe his entire youth. It was here that Catholic, Muslim, and Jew all met, bought, sold, traded, had sex, and did about everything else that humans can do with each other.

By the time Frederick was ready to become Holy Roman Emperor, the man was a thorough Sicilian in matters of culture from the language he normally preferred to speak to the weather he preferred and the food he liked. He had not been to Germany and had no real desire to go. He did, as he knew he had to. He went, and quickly realised that the easiest way to get the troops and money he needed to get his title was to let the recalcitrant nobles have their way in terms of their feudal rights and then some. He quickly left the country, and only went back once or twice more in his life for short periods. Otherwise he left Germany to his son Henry (and later Conrad) to control in his absence.

Now this may have been a FINE method to get money for his pocket and troops for the army. But it was disastrous for Germany! As Germany became more and more feudalised, the likelyhood of it EVER developing a centralised nation-state became slimmer and slimmer. And after the fall of the Hohenstaufen Dynasty, the idea of bringing Germany and Italy together into one Imperium fell with it. As a result, NEITHER country was able to unify until 1870 (Italy) and 1871 (Germany).

So what can be said of Frederick in the end? A brilliant man. He thought in terms of what could be done at the beginning of his rule. Although he had some grandiose ideas which I shall present in my book, I think that he was perhaps a little TOO grandiose, and not in the right way. He focused on unifying two countries into the HRE when two separate nations in personal union would have been a safer bet.

If I say anything more, then you won't have reason to buy my book, so there you are.

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    "NOT run by the Church (thank God)." <- Gold. +1
    – AndreiROM
    Commented May 11, 2016 at 3:10

There is a strong probability that the stories about his experiments were lies circulated by his enemies. The story about the child experiment has also been told about other historical characters, for example. I suppose that the story tellers considered him to be evil not so much for harming people cruelly but for questioning and experimenting with topics which were part of religion.

  • This would be a stronger answer if you quoted some sources to support your argument.
    – Steve Bird
    Commented Jan 14, 2016 at 6:21
  • The story of the children appears already in Herodotos; the general idea has its own Wikipedia article, where Frederick is mentioned en.wikipedia.org/wiki/Language_deprivation_experiments
    – andejons
    Commented May 13, 2016 at 8:52

Frederick II. was in opposition to the popes. Stories presenting him in bad light are nowadays attributed to the popes' propaganda.

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