Di Renjie, courtesy name Huaiying, from Taiyuan in Bingzhou, was a renowned minister of the Tang Dynasty.
When Di Renjie first served as a minor official in Bianzhou, he caught the eye of Yan Benli, the imperial inspector for Henan Circuit, who recommended him to be a legal advisor in Bingzhou. One day, his colleague Zheng Chongzhi was ordered on a distant mission, but his mother lay ill. Seeing Zheng's distress, Di Renjie said, "Your mother is elderly and sick—how could you leave her?" He then approached their superior, Lin Renji, and volunteered to take the mission himself so Zheng could care for his mother.
After learning the full story, Lin Renji not only granted Di Renjie's request but was deeply moved. At the time, Lin Renji was at odds with his colleague Li Xiaolian, the military commander, often clashing over decisions. Lin Renji approached Li Xiaolian and said, "Di Renjie and Zheng Chongzhi both serve as legal officials, yet Di willingly takes on hardships for himself while offering convenience to others. Reflecting on Di's noble conduct, shouldn't we feel ashamed of our own discord?" From that day on, the two reconciled, and they gave Di Renjie the highest praise: "In virtue, Di Renjie stands alone—south of the Big Dipper, there is only one such man!"
A series of events soon proved that assessment was not an exaggeration. During the Yifeng era, Di Renjie was appointed as a judge in the Supreme Court and cleared 17,000 backlogged cases in a single year, with no appeals filed due to his fair rulings. When General Quan Shancai of the Imperial Guard accidentally cut down a cypress tree at Emperor Taizong's mausoleum, Emperor Gaozong Li Zhi declared this made him an unfilial son and insisted on the death penalty. Di Renjie argued that dismissal was sufficient, not execution. When the emperor persisted and other officials urged silence, Di Renjie countered, "During Emperor Wen of Han's reign, when someone stole a jade ring from the High Temple, Chief Justice Zhang Shizhi fiercely debated the punishment with the emperor. An enlightened ruler listens to reason, and a loyal minister is never intimidated by force. If Your Majesty ignores my advice, how will I face Zhang Shizhi in the afterlife? The law clearly prescribes punishments for crimes—you cannot execute someone who does not deserve death. If you kill a general over a single tree at the mausoleum, how will history judge you a thousand years from now? I refuse to obey your order to execute Quan Shancai and make you a tyrannical ruler."
After Li Zhi calmed down, he agreed not to execute Quan Shancai and promoted Di Renjie to imperial advisor.
"Dou Nan Yi Ren" is an abbreviation for "South of the Big Dipper, there is only one person," meaning unparalleled in the world, used to describe someone whose virtue and talent are universally admired and second to none.
Source: *New Book of Tang*, "Biography of Di Renjie"
Meaning of the Idiom: Later, the Chinese idiom "斗南一人" came to describe how someone whose virtue and talent are universally admired and second to none.