Ryu Seong-ryong
Chief State Councillor of Joseon
"I write this so that those who come after may know how it happened, and not let it happen again."
Biography
The Confucian scholar-official who held the Joseon state together while it disintegrated, and who is on this list mainly because of one appointment. In 1591 he pushed an obscure, twice-demoted officer named Yi Sun-sin into the Jeolla naval command over the objections of men with better connections. It was, on any reasonable accounting, the single most consequential personnel decision in Korean history. He had also argued for years that the Japanese were coming and that the country was unprepared, against a court that had sent two envoys to Japan and received two opposite reports and chose to believe the reassuring one. When the invasion came he ran the war effort: he organised supply for the Ming army, coordinated the guerrilla militias, and kept a fleeing king functioning as a government. He was forced out by factional enemies in 1598 on the very day Hideyoshi died, and went home to write the *Jingbirok* — the Book of Corrections — a brutally honest account of how his own government's factionalism, complacency, and contempt for military affairs had nearly destroyed the country. It is one of the great works of self-examination in any language, and it is the reason we know this war in the detail we do.
Did you know?
He wrote the *Jingbirok* — a merciless account of his own government’s failures — so that Korea would never repeat them. It was later banned in Japan after copies were smuggled there and sold well.
Key Battles
The Fall of Hanseong
Toyotomi Japan victoryJune 12, 1592 · 500 total casualties
The speed is the story: 450 kilometres in three weeks against a state that had been at peace for two hundred years. But the burning of the slave registers by Koreans, before any Japanese soldier arrived, says something else — the dynasty had lost its people's loyalty before it lost its capital. Seonjo's flight nearly ended the Joseon dynasty then and there, and he was still considering crossing into China when the news came from the sea.
Battle of Okpo
Joseon Korea & Ming China victoryJune 16, 1592 · 1,000 total casualties
Yi Sun-sin had been demoted, imprisoned, and reduced to the ranks earlier in his career for refusing to flatter superiors, and had been posted to an obscure southern command in 1591 on Ryu Seong-ryong's recommendation. He used the posting to build a fleet for a war nobody else believed was coming. Okpo was the first sign that the sea would be a different war entirely.
The Recapture of Pyongyang
Joseon Korea & Ming China victoryJanuary 8, 1593 · 12,000 total casualties
The moment the war became a world war. The Ming came because Korea was the shield of Beijing — Hideyoshi had announced he was coming for China and they believed him. Chinese artillery answered Japanese arquebuses, and the strategic balance flipped. It also nearly bankrupted the Ming: the campaign cost roughly ten million taels, a debt the dynasty never recovered from and which historians still cite among the causes of its collapse fifty years later.
Life Journey
Timeline
November 7, 1542
🌅 Birth
Born in Uiseong to a scholar-official family
1562
📚 Education
Studies under the philosopher Yi Hwang
February 13, 1591
📍 Posting
Appoints Yi Sun-sin to the Jeolla naval command
June 12, 1592
⚔️ Battle
Flees north with the court as Seoul falls
January 8, 1593
⚔️ Battle
Coordinates the Ming intervention at Pyongyang
September 18, 1598
🕊️ Postwar
Forced from office the day Hideyoshi dies
May 31, 1607
✝️ Death
Dies at Andong, having written the Book of Corrections