History is replete with weird, unsettling and downright shocking events. You need only pick up the nearest textbook to find evidence for it. There are some things, however, that never make it into these books, simply because they are too strange, gruesome or plain disturbing for the average person to take in. Following in the vein of the previous list, we bring you 20 messed-up facts about history that you never learned in school.

Warning: NSFW and potentially triggering content. 

1 Peter the Great beheaded his wife’s lover, then forced her to keep his head in a jar of alcohol in their bedroom.

Peter I “the Great” was certainly the most messed-up member of the Romanov family that ruled Russia from 1613 to 1885. He took the reins over from his sister Sophia when he was merely a lad of 17 and changed the face of Russia forever, among other things. After shipping off his then-wife to a convent, Peter married his court-mistress Martha Scavronsky (who later changed her name to ‘Catherine’). Although Peter Romanov was known for his forgiving nature, he could not tolerate infidelity. When he caught wind of Catherine’s affair with William Mons, Peter had him beheaded, then forced his wife to put his head in a jar of alcohol in their bedroom. It remained there until Peter’s death in 1725.(source)

2 Wealthy Europeans in the 16th and 17th century routinely ingested medicines that contained human blood, bones, and fat, believing that they could cure all ailments.

Cannibal medicine, as primitive and gruesome as it may sound, was a shockingly common practice during the times. With nobody voicing their dissent over the ethics of the practice (although there were many), physicians, chemists and gravediggers alike prospered in this business. Richard Sugg, the author of Mummies, Cannibals and Vampires: The History of Corpse Medicine from the Renaissance, says of this peculiar period in history,

“The question was not, ‘Should you eat human flesh?’ but, ‘What sort of flesh should you eat?’ ”

It began with crumbling Egyptian mummies into tincture form, which was used to stop all kinds of internal bleeding. Soon followed human skulls, which were taken in powdered form to cure headaches or mixed with chocolate to treat apoplexy. German doctors soaked bandages in human fat and used it for wrapping wounds, in addition to prescribing it as a remedy for gout.

Blood was considered good for drinking, and best when consumed as fresh as possible. Although this practice seemingly was not all that widespread, the poor and destitute who could often not afford to go to the apothecary took maximum advantage of it. They gathered in hordes during public executions and were given a cup of blood from the condemned in return for a small amount of money.(source)

3 Nazi scientist Josef Rudolf Mengele carried out sick experiments in his lifetime: He tried to turn the eyes of Jewish children blue, infected deliberately inflicted wounds with Mustard gas and even sewed a set of twins together.

After being pronounced unfit for duty in 1942, Dr. Joseph Mengele was sent as a volunteer to Hitler’s death camp: Auschwitz. The 21-month stay at the concentration camp earned him the nickname, “The Angel of Death”, owing to the fact that he was the brain behind nearly all of the atrocities that took place at Auschwitz. Mengele was the primary provider of gas chambers for the camp. When he received news that an entire block was infected with lice, he proceeded to gas all the 750 women who were assigned to it. Children and

Mengele was the primary provider of gas chambers for the camp. When he received news that an entire block was infected with lice, he proceeded to gas all the 750 women who were assigned to it. Children and twins, in particular, held a twisted fascination for Mengele. He routinely conducted horrifying experiments on identical twins; bleeding them to death, injecting chloroform into their hearts and even sewing a pair together to create Siamese twins. It is said that the children had screamed so much that their mother had to kill them.

The full extent of Mengele’s experiments will never be known, as they were conducted in strict secrecy. The reports that were shipped to the Kaiser Wilhelm Institute in two trucks were destroyed, and those that Mengele took with him to South America were never found.(1,2)

4 In 1958, the government funded an experiment to determine whether or not dolphins could speak. This later escalated to the female researcher giving the dolphin handjobs and then later taking LSD with the dolphin.

Anything for science.

John C. Lilly, the neuroscientist who was overseeing the research, never anticipated that Peter the dolphin would become romantically attached to his assistant Margaret Howe. Studies in the area of language and development were gaining massive traction, which was all the impetus Lilly needed to test out his bizarre hypothesis. Margaret played, talked, trained, and even slept with Peter on a saltwater bed so she could have maximum interaction with the dolphin. Peter learned fast, and in no time began wooing Margaret. He nibbled at her feet and

Peter learned quickly, and in no time began wooing Margaret. He nibbled at her feet and legs and then acted out aggressively when she didn’t respond to his advances. Peter hit Margaret’s shins with his nose and flippers until they bruised. Lilly was averse to sending Peter back to his colony for a mating session because he could risk undoing everything the dolphin had learned. So he stayed, and seemed to behave in a much more welcoming manner with Margaret after that. He resumed his courting behaviour by baring his genitals to her, and somehow it worked. Margaret stroked his erection and the dolphin was more co-operative with his language lessons after that.

Did we mention that Dr. Lilly lost funding for the research (and his credibility) after tripping on LSD with the dolphin and the team? Yeah. That happened.(source)

5 Thomas Edison electrocuted an elephant for killing three men.

Of the three, one was a trainer, who burned her with a lit cigar when he was drunk and the other two were keepers who struck her with a pitchfork. In 1875, Topsy the elephant was smuggled out of Asia as a baby and brought to America to perform in the Forepaugh circus. She was the star of the show, but behind the curtains and big-top tents was a much darker reality.

Circus animals were treated with utmost cruelty by the trainers, and shockingly it was common knowledge and even encouraged. Training methods included beatings, burning the flesh with hot pokers and even firing at them with guns to make them obey. Topsy would not take this, however, and began to gain a reputation for lashing out at trainers who mistreated her, even killing them in the process. No zoo would take her because of this, and the decision to euthanize her was made.

This presented a massive problem; there was no effective way to kill an elephant of such size – Topsy stood 10 ft. tall and weighed three tons. The owners of Luna Park turned to Thomas Edison, who in 1903 had gained a powerful presence in the media with his electrical inventions. By then, Topsy had been branded as a killer rightly being condemned to death, so when the date of execution came, people watched. In full view of the American public, and taped on the newly-invented movie camera, Topsy was electrocuted to death by Edison’s team on January 4, 1903.(source)