In 399 BCE, the Athenian government put the philosopher Socrates on trial. The charges: corrupting the youth and refusing to acknowledge the Greek city-state’s gods.

Socrates was found guilty—and received a death sentence that he carried out himself rather than renounce his beliefs. Contemporary accounts say the roughly 70-year-old philosopher killed himself by drinking poison, which historians have traditionally believed to be hemlock. Two centuries later, French artist Jacques-Louis David portrayed the famous poisoning in his 1787 painting “The Death of Socrates.”

In 1513, Spanish conquistador Juan Ponce de León led an expedition into what’s now Florida, allegedly searching for a rumored fountain of youth. His attempt to colonize the territory for Spain ended when Indigenous Calusa people attacked him and his fellow invaders.

A member of the Calusa reportedly shot Ponce de León with an arrow dipped in the milky white sap from a manchineel tree, which is highly poisonous to humans. (One touch of its bark can cause excruciating blisters, while one bite of its fruit can prove fatal.) The European invaders brought Ponce de León to Spanish-controlled Cuba, where he died from his injuries.

American Charles Francis Hall was an Arctic explorer and joint commander on the Polaris expedition, a failed attempt to reach the North Pole. In late October of 1871, Hall began complaining of gastrointestinal issues and other health problems, and accused members of the expedition of poisoning him. Two weeks later, he died in his cabin.

In the 1960s, researchers performed an autopsy on his body and found elevated levels of arsenic in the parts of his hair and fingernails grown during the last two weeks of his life, suggesting that Hall’s suspicions were correct. However, the identity of the person who poisoned him remains a mystery.

In 1875, at the age of four, Guangxu became emperor of the Qing dynasty, the last imperial dynasty to rule China. An 1898 coup effectively removed him from power and placed him under house arrest, where he spent the rest of his life.

When Guangxu died in 1908 at the age of 37, after a decade under house arrest, there were suspicions of poisoning. But imperial records indicated he died of natural causes. It wasn’t until 2008, a century after Guangxu’s death, that modern researchers revealed the rumors were true: Examinations of his body indicated that it contained extremely high levels of arsenic. As with Hall’s death, who poisoned him remains a mystery.

The controversial Russian mystic Grigori Rasputin gained lasting notoriety not just for being poisoned, but for reportedly surviving the poisoning. An illiterate peasant known for his licentious behavior, Rasputin nonetheless developed a close relationship with Tsar Nicholas II and his family, the last imperial family to rule Russia before the 1917 Russian Revolution. In December 1916, Prince Felix Yusupov and his associates conspired to kill Rasputin by serving him food and drink laced with potassium cyanide.

When the poison didn’t appear to knock Rasputin out, Yusupov and his conspirators shot and drowned the mystic. Yusupov’s account of the events helped turn Rasputin into a legendary figure, sparking several theories about how he may have survived the poisoning.

A leading Ukrainian nationalist militant, Stepan Bandera went to prison in the 1930s for his involvement in the assassination of a Polish official. Released in 1939 after Germany invaded Poland, Bandera allied with the Nazis, who shared his antisemitism and opposition to the Soviet Union.

Bandera died in West Germany in 1959, and at first, police in Munich suspected he had committed suicide with cyanide. However, when the KGB agent Bohdan Stashynsky defected to West Germany twoa few years later, he confessed that he’d killed Bandera by shooting cyanide gas into Bandera’s face with an air pistol. (Stashynsky wore a gas mask to protect himself.)

In November 2017, former Bosnian Croat military commander Slobodan Praljak stood before a United Nations tribunal in The Hague to appeal his 20-year prison sentence for war crimes. When the judge upheld his sentence, Praljak declared he was not a war criminal, and then quickly drank something from a vial. He then announced to the shocked courtroom that he had just swallowed poison.

Praljak died hours later at a hospital, but the video of him taking the poison was livestreamed on the court’s website. The footage of Praljak’s suicide spread online, becoming a meme. An investigation revealed he had poisoned himself with potassium cyanide. The Hague Public Prosecution Service never determined how Praljak, then being held at the UN Detention Unit, obtained the toxin.