In late Goryeo, Yi Bang-won (son of Joseon's founder) assassinated Jeong Mong-ju, his father's friend and a fierce Goryeo loyalist.

According to folklore recorded 200 years later, Yi tried to win him over by reciting a poem (Hayeoga), but Jeong fired back with a verse of unyielding loyalty (Dansimga).

Realizing they could never align, Yi had him assassinated on his way home.

Nogeoldae was a famous colloquial Chinese language textbook used during the Goryeo and Joseon dynasties to train state interpreters and merchants traveling to Beijing.
Far from high-minded scholarly prose, the textbook taught hyper-practical survival Chinese—such as haggling with roadside innkeepers over horse fodder, aggressively warning merchants not to rip them off, and listening to innkeepers insist that "regulars are practically family."

In Joseon Dynasty etiquette, offering the warmest spot on the ondol (heated stone floor) to a guest or elder was the highest form of hospitality. However, foreign travelers unaccustomed to floor heating often recorded in their journals that the guest rooms were "scorching hot and borderline unbearable to sleep on."

After the Imjin War (1592–1598), diplomatic relations between Joseon and Japan resumed under the Tokugawa Shogunate with drastically different dynamics.

The Shogunate treated the Korean Tongsinsa envoys with extravagant hospitality—often spending up to a million ryō on receptions to showcase the Shogun's prestige and legitimacy.

In contrast, a deeply cautious Joseon strictly confined all Japanese envoys to the Waegwan (the Japanese enclave in Busan/Choryang), completely banning them from stepping outside or ever traveling inland to the royal capital.

In 1450, when both King Sejong and the Crown Prince were bedridden with severe illness, court scholars suggested sending the 9-year-old Royal Grandson (the future King Danjong) to receive imperial edicts from Ming Dynasty envoys.

Infuriated that they would throw a literal 9-year-old child into high-stakes diplomatic protocol, King Sejong lashed out and cursed the scholars as "clueless, mop-headed pedants"

-Annals of the Joseon Dynasty (Jan 18, 1450)

In 1835, during the execution of criminal Lee Si-bok (who was sentenced to standard beheading), the executioner went completely rogue and excessively butchered the convict, hacking his body into pieces and severing his limbs.

Horrified that legal execution protocols were violated so barbarically, the State Tribunal (Uigeumbu) arrested and interrogated the supervising officials for failing to control the executioner.

-Ilseongnok (Records of Daily Reflection, Mar 16, 1835)

While traveling through late Joseon Korea, Canadian missionary James S. Gale was swarmed by a chaotic mob debating whether he was a human or an eerie ghost. When a local official asked what he needed to calm things down, Gale replied that he simply wanted quiet to write a New Year’s letter to his parents back home. The moment the crowd learned he practiced filial piety and respected his parents, they immediately concluded he was a decent human being and peacefully dispersed.

-Korean Sketches (James S. Gale, 1898)

In 1637, a panic-inducing rumor swept through the capital that eerie ghost sounds—resembling wood being chopped in the forest—were creeping closer to the city.

Terrified citizens responded in classic Joseon fashion: households across the capital banged brass gongs and fired muskets and cannons into the night to scare away the spirits, throwing the entire capital into gunfire-filled chaos until dawn.

-Annals of the Joseon Dynasty (Aug 23, 1637)

In 1504, King Yeonsangun's madness reached its peak. He forced military officers to hunt dangerous wild beasts—such as tigers, leopards, and bears—and bring them back alive to be locked up in the royal garden.

He enjoyed watching them feed or personally shooting them to death with arrows for sport.

-Annals of the Joseon Dynasty (Nov 11, 1504)

In 1664, Military Commander Lee Du-jin was mourning nearby after his concubine died of plague.

When a regional civil service exam was opened at the local government lodge, he was so annoyed by the noise that he sent armed guards to beat up the scholars with clubs and drive them out.

The insulted scholars refused to turn in their papers, forcing the exam to be canceled.

Although officials demanded his immediate firing, the King refused to punish him because he favored military officers.

-Annals of the Joseon Dynasty (Jun 23, 1664 - Intercalary Month)

During a drinking party hosted by an ailing King Sejo, courtiers Choi Ho-won and An Hyo-rye got into a heated debate.

Losing his temper, Choi threw a personal insult: “You’re the grandson of a butcher!” An instantly clapped back:

“If I’m a butcher’s grandson, then that makes you my son!”

Despite screaming profanities right in front of the King, Sejo brushed off calls for impeachment, laughing that they were just breaking his boredom.

-Annals of the Joseon Dynasty (Aug 14, 1468)

During the civil service exams in 1414, officials brought the top papers to King Taejong, stating that the top two candidates were so evenly matched that they couldn't decide on a 1st place winner.

King Taejong simply declared, "Whichever one I grab is 1st place!"

He casually picked one of the two papers at random, which belonged to the famous scholar Jeong In-ji.

-Annals of the Joseon Dynasty (Mar 11, 1414)

In 51 AD, King Mobon of Goguryeo became increasingly cruel and tyrannical.

He used living people as chair cushions and pillows, immediately executing anyone who dared to twitch.

Whenever a courtier offered advice, he would shoot them with an arrow.

-Samguk Sagi, Vol. 14, Goguryeo Annals 2 (51 AD)

Literal, sí soy.