Jeong Mong-ju and the Song of a Loyal Heart: Goryeo's Last Great Scholar and the Bridge Where He Died

Jeong Mong-ju (1337–1392), also known by his art name Poeun, was a scholar, diplomat and statesman of the late Goryeo dynasty who tried to reform the declining kingdom while keeping it alive; he opposed the general Yi Seong-gye, founder of the coming Joseon dynasty, and was assassinated on Seonjuk Bridge in Kaesong in 1392, the year Goryeo fell. His poem of loyalty, the Dansimga, is one of the most famous poems in Korean, and his death came to symbolise unwavering faithfulness.

A brilliant scholar

Jeong Mong-ju is remembered as the last great figure of late Goryeo, outstanding in scholarship, diplomacy, economics, military affairs and politics. At the age of 23 he passed three different civil service examinations, receiving the highest possible marks on each. He became a leading Neo-Confucian scholar, helping to spread the teachings that would later shape Korean society for centuries.

Envoy to Ming and Japan

Jeong was also a skilled diplomat. In 1372 he was sent as an envoy to the Ming dynasty in China. At a time when attacks by Japanese pirates, the waegu, on the Korean Peninsula were severe, he was sent in 1377 as a delegate to Kyushu in Japan to negotiate. These missions were dangerous and delicate, and they show how much the court trusted his judgement.

Between reform and revolution

At first Jeong supported Yi Seong-gye, a powerful general who took control of the court after the Wihwado Retreat of 1388, and he agreed with some of Yi's moderate reforms. But he soon realised that Yi and his more radical supporters, such as Jeong Do-jeon, wanted not to reform Goryeo but to replace it with a new dynasty. Jeong chose to defend the old kingdom.

A poem answered with a poem

According to tradition, Yi Seong-gye's fifth son, Yi Bang-won, tested Jeong's loyalty at a gathering by reciting a short sijo poem, the Hayeoga. Its message: what does it matter if we do this or that? Like the arrowroot vines on Mansu Mountain, let us twist together and enjoy a hundred years. Jeong replied with his own sijo, the Dansimga, "Song of a Loyal Heart": even if this body dies and dies again, a hundred times over, and my bones turn to dust, and my soul may or may not remain, how could my single-minded heart for my lord ever change? The exchange made his answer clear.

Death on Seonjuk Bridge

On 9 April 1392, Yi Seong-gye was seriously injured in a riding accident, and Jeong planned to use the moment to break Yi's faction. But Yi Bang-won brought his father back to the capital, and Jeong's plan failed. Soon afterwards, on 4 May 1392, Jeong was attacked and killed by Yi Bang-won's men on Seonjuk Bridge in Kaesong. A popular legend says that a bamboo grew beside the bridge and that reddish marks on its stones are his blood that never washed away. That same year, Goryeo, which had lasted 474 years, came to an end, and the Joseon dynasty began.

Honoured by his enemies' descendants

Remarkably, Jeong was later venerated even by Joseon kings, including the descendants of the man who had him killed. The new dynasty valued loyalty, and his refusal to change sides became the model of a faithful subject. Today a pattern in ITF taekwondo is named Po-Eun in his honour, symbolising his unwavering loyalty.

Learn with Jeong Mong-ju: English phrases

Phrase	Meaning	Example
unwavering loyalty	loyalty that never changes	He showed unwavering loyalty to his friends.
to stand your ground	to refuse to give up your position	She stood her ground in the meeting.
to change sides	to join the opposing group	He refused to change sides.
a man of principle	someone who keeps to his beliefs	Jeong was a man of principle.
the end of an era	when an important period finishes	His death marked the end of an era.

Try this: Write three English sentences about a time you stayed loyal to something, using "to stand your ground" and "unwavering".