He was notorious for being corrupt and for dominating the Ming government for two decades as Grand Secretary during the reign of the Jiajing Emperor.

His father, a scholar who had repeatedly failed the imperial examination, while put great effort into educating his son from childhood.

His early career was quickly cut short by a severe illness which forced Yan Song to return to his hometown, though this proved to be a blessing in disguise, since it kept him away from the imperial court just as it was under the domination of powerful eunuch Liu Jin.

[1] During his second term as Senior Grand Secretary, he and his son Yan Shifan [zh] dominated court politics with the tacit consent of the fatuous monarch who shirked his responsibilities as emperor and devoted much of his time to sensual pleasures and Taoist practices.

He was the subject of the Chinese opera called Beating Yan Song (打嚴嵩 Dǎ Yán Sōng).