Fang Xuanling was a founding hero of the Tang Dynasty.
From a young age, Fang Xuanling was sharp and intelligent, devouring books and excelling at writing, with his cursive and running scripts also highly impressive. He once quietly told his father, 'Though the Sui Dynasty appears unified and peaceful, the emperor lacks virtue and merit, surrounds himself with flatterers, slaughters the innocent, and has the people seething with resentment; he even capriciously deposed the crown prince. The Sui Dynasty's fall is imminent!'
His father, terrified, quickly shouted, "You beast, don't talk nonsense!"
Fang Xuanling passed the imperial examination at eighteen and was appointed as a cavalry officer. The Vice Minister of Personnel, Gao Xiaoji, held Fang in high regard and once told others, "I have seen many people, but never one as loyal and learned as Fang Xuanling. He will surely become a pillar of the state."
Later, when the Han King Chen Youliang rebelled against the Sui Dynasty, Fang Xuanling was implicated and exiled to Shangjun.
Fang Xuanling heard that the renowned Prince of Qin, Li Shimin (later Emperor Taizong of Tang), was on a campaign north of the Wei River, so he rushed to join him, arriving at the military camp so hastily that he still held his horsewhip as he sought an audience at the gate.
When Li Shimin first met Fang Xuanling, he felt an instant connection—like old friends reunited after years apart, both lamenting they hadn't met sooner. Without hesitation, Li Shimin appointed Fang Xuanling as his personal secretary in the prince's mansion.
From then on, Fang Xuanling followed Li Shimin across the land, surviving countless brushes with death. After every victory, while other generals scrambled for gold and treasure, Fang Xuanling scoured the battlefield for talented men to serve his lord. No wonder Li Shimin once remarked, "Emperor Guangwu of the Han Dynasty had Deng Yu to unite his advisors in harmony; today, I have Fang Xuanling—he is my very own Deng Yu."
In 627 AD, after Emperor Taizong of the Tang Dynasty ascended the throne, he declared Fang Xuanling, along with Du Ruhui, Zhangsun Wuji, Yuchi Jingde, and Hou Junji, as the top contributors to his reign, appointing Fang Xuanling as Zhongshu Ling, the chief chancellor.
Later, the idiom "Friends at First Sight" came to describe meeting someone for the first time as if they were an old friend.
Source: *New Book of Tang*, "Biography of Fang Xuanling"
Meaning of the Idiom: Later, the Chinese idiom "一见如故" came to describe meeting someone for the first time as if they were an old friend.