Cao Xian (541–645), a native of Jiangdu County, Yangzhou, was a scholar of the Chen dynasty, the Sui dynasty, and the Tang dynasty.[1] [2]
He was ordered by Sui Yang Emperor to order and edit the hundred volumes《桂苑珠丛》. He also authored a number of studies and commentaries including 《博雅音》, 《古今字圖雜錄》, 《文字指歸》, 《小學總錄》, 《揚州記》, 《文選音義》. He advised Emperor Taizong of Tang on understanding of classical texts.[3] After retiring from imperial service he taught many disciplines.