Yelü Yanning was born in 946 into the Yelü clan -- the imperial family of the Khitan-ruled Liao dynasty. His family belonged to the inner circle, holding a place in the horizontal gers of the Khitan Khan. Bravery ran in the blood. His great-grandfather Nieligu, grandfather Zhiwubu, and father Sage were all known as fierce warriors who repeatedly accomplished meritorious deeds. When the Jingzong Emperor ascended the throne, the young Yanning was recruited as a palace attendant, beginning a career of service that would carry him from the imperial court to the farthest reaches of the empire. Title upon title accumulated: "righteousness-defending outstanding minister," "acting grand protector," "senior general of the left imperial insignia guard," "imperial censor in chief." He was granted a fief of 500 families.

Yanning earned something rarer than titles: the deep trust of both the Jingzong Emperor and the formidable Empress Xiao Chuo. He performed his guard duties with such devotion that when the emperor died in 982, the epitaph records that Yanning "wished he could follow him in death." The empress, now regent for her young son, rewarded this loyalty with even grander honors -- military governorship, the rank of acting grand marshal, honorary chancellor. His fief grew to 700 families. In an era when court politics could be lethal, Yanning's unwavering fidelity made him indispensable to the throne, a rarity in a world where shifting alliances were the norm.

Yanning's final mission took him far from the court. The Zubu confederacy -- likely the Keraites -- in central Mongolia had raised armies against the Liao dynasty, their push eastward threatening the Niaogu, Dilie, and Shiwei peoples along the northern frontier. Emperor Shengzong and Empress Xiao dispatched Yanning to pacify the borderland. He marched into the vastness of present-day Hulunbuir in Inner Mongolia, near the source of the Heilongjiang River, then continued to the Kherlen River in what is now eastern Mongolia. He succeeded in his mission, but the campaign cost him his life. On December 30, 985, at the age of 39, Yelü Yanning died from complications of wounds sustained in the fighting. His body was carried back to Chaoyang County, where the memorial stone was placed at his burial site.

The inscription's historical value extends beyond Yanning's biography. The Khitan large script -- one of two writing systems created for the Khitan language -- is still only partially deciphered. Most identifiable words in the Khitan portion of this memorial are borrowings from Chinese, but the text preserves genuinely Khitan vocabulary, including the word for "hundred," one of the earliest fully deciphered Mongolic words in any inscription. A rubbing of the epitaph was first published in 1980, and scholars have been working to unlock its meanings ever since. The stone now resides in the Liaoning Provincial Museum, a quiet testament to a warrior whose story survived only because someone carved it into rock on a mountainside, where it waited nearly a thousand years to be read again.