Murder by poisoning is usually associated with medieval palace intrigues or detective novels, but last month, Alexei Navalny, a prominent opposition figure in Russia, was allegedly poisoned at an airport cafe in Siberia. A campaigner against government corruption and fierce critic of Russian President Vladimir Putin, Navalny fell violently ill and remains a coma after his tea was apparently tampered with. He is the latest in a long line of the Kremlin’s political opponents suspected to have been poisoned. During the Cold War, the Soviet Union devised inventive ways of doing away with dissidents both at home and abroad. Exotic methods of delivery included cyanide spray guns secreted in newspapers and poison-tipped umbrellas. Modern Russia seems to have continued this tradition. Poisons were also widely used in China’s past. Compared to swords, axes and other arms, poisons were easily hidden and administered, they killed quickly with minimal mess, and the victims’ bodies remained intact. For these reasons, poison was the murder weapon of choice for many regicides. If one’s target was a ruler, a gruesome death would be deemed indecorous. The Han period (202BC-AD220) saw several emperors assassinated by poison, including children. A feature of Han politics was the young age of its emperors, and the political domination of empress dowagers – often not their biological mothers – and their families. When the young emperors were no longer useful, or began to challenge the status quo, they would be killed by their puppeteers. Western Han dynasty emperors Ping and Zhi were aged 14 and nine, respectively, when they were poisoned in AD6 and AD146. The Eastern Han’s Emperor Shao was deposed at age 14 and forced to ingest poison a year later by kingmaker Dong Zhuo, who had installed a new emperor. Some emperors were poisoned by their relatives. The Sui dynasty’s Emperor Wen was murdered by his own son – one story has it that poison was administered to hasten his demise in AD604 after he revealed his intention to alter the succession plans. In the Tang dynasty, Emperor Zhongzong had a formidable mother, Empress Wu Zetian , who had reigned as empress regnant, and an ambitious wife, Empress Wei, and daughter, Princess Anle. Wei and Anle decided Zhongzong was an obstacle to their desires of becoming reigning empresses and, in AD710, mother and daughter teamed up to have Zhongzong killed by poison. But a month later, the vile pair were decapitated in a coup led by members of the imperial family. In a more recent case of regicidal poisoning, the Guangxu Emperor died on November 14, 1908, exactly one day before his nemesis, Empress Dowager Cixi , breathed her last. It was rumoured that Cixi had ordered the 37-year-old Guangxu’s murder when it became apparent she was about to die. In 2008, a full century later, toxicology tests on his remains and clothing confirmed the young reform-minded emperor had died of arsenic poisoning. However, the identity of his murderer or the mastermind behind it has yet to be established.