Despite being born into a wealthy family, his beginnings were humble, and his lifestyle would best be described as spartan. He paid little heed to his own clothes and meals, and eschewed fine garments or other comforts even when he became famous and could easily have enjoyed them. He disliked men who desired expensive articles, and he viewed simplicity as a virtue. His motto, left to him by his father, was "Do not be covetous of gold".

Military career
Such a man was well suited for military service, and Choi quickly gained the confidence of both his men and his king during numerous battles with Japanese pirates who began raiding the Korean coast around 1350.
At 36 years of age he became a national hero when he successfully put down a rebellion by Cho Il-shin after the insurgents had surrounded the palace, killed many officials and had proclaimed Cho king. Then, in 1355, the Red Turban Rebellion took place in areas of the troubled Mongol Yuan Dynasty that occupied China. As Goryeo was a tributary state of the Yuan since 13th century, Choi Yong was sent to help the Mongols squash the rebellion, and his success in nearly thirty different battles won him even more fame and favour at home. Upon returning to Korea, he dutifully reported to King Gongmin the internal problems experienced by the waning Yuan Dynasty, which gave the king the idea that the time was right to reclaim some of the northern territories previously lost to the Mongols. Choi fought to recover various towns west of the Yalu River, to the great delight of his king.

He served briefly as the Mayor of P'yŏngyang, where his efforts at increasing crop production and mitigating famine won him even more attention as a national hero. In 1363, he distinguished himself further when a powerful minister named Kim Yon-an tried to overthrow the government. Choi gathered up his forces and defeated a Mongol force of 10,000 which subsequently attacked Goryeo in support of the rebellion.


Betrayal and redemption
Following a dream that he thought predicted that a Buddhist monk would save his life, King Gongmin promoted a monk named Shin Don to a lofty position within his court, and allowed him considerable influence. At first Shin Ton toiled to improve the lives of the peasants with great opposition from the ministers.
However with the king's support he grew increasingly ruthless and corrupt, and Choi – who vigorously opposed corruption in the kingdom – found himself at odds with him. Subsequently, Shin Ton engineered false accusations of misconduct against Choi that resulted in a punishment of six years in exile, and brought him dangerously close to execution. However, when Shin Ton died, Choi Yong was restored to his previous position and was immediately asked to prepare a fleet to fight the Japanese pirates and eliminate the remaining Mongol forces on Jeju Island. He engaged the Mongols first, who fought tenaciously, but Choi's forces eventually freed the island. Then, in 1376, the Wokou pirates advanced into Goryeo and captured the city of Gongju. Chong Mong-Chu secured assistance from the Japanese Shogun to eliminate these pirates, but the Japanese were of little help. With the new gunpowder discovered by scientist Choe Mu-seon, General Choi Yong and his subordinate Yi Seonggye managed to rout and eventually defeat the pirates and reclaim Gongju.

Final years
The Ming Dynasty in China had become powerful during the 14th century, and had driven back the Yuan to Mongolia and occupied Manchuria and parts of north-eastern Goryeo. In 1388, General Yi Seonggye was ordered to use his armies to push the Ming armies out of the Korean peninsula and invade Liaodong. However, Yi, knowing the support he enjoyed from both the high-ranking government officials and the general populace, he decided to return to the capital, Kaesŏng, and trigger a coup d'etat. This incident later became famous as the Wihwado Retreat, and became the first sign of the change of dynasty.

When Yi returned to the capital, Choe Yong put up a gallant fight at the palace, but was overwhelmed by Yi's forces. Records differ as to what happened next,
although it seems likely that after his defeat, Choi was banished to Goyang. He was later beheaded in the name of the government controlled by Yi Seonggye. Before the execution, he was famously known to have predicted that grass would never grow on his grave, due to his unjust demise.
Interestingly, grass never did grow on his grave, and it was known as joekbun, which means red grave, because of the red soil. In 1979, the first sprouts of grass were found growing from General Choi's grave.

Legacy
There have been many judgements about General Choi as there had been about Yi Seonggye. Some people consider him a great general who was wholeheartedly devoted to the protection of his country, while others consider him to be a strict conservative tyrant who ursurped the government. However, he risked his life many times for Goryeo, and his unswerving loyalty eventually cost him his life.