The Song conquest of Northern Han () occurred in 979, when Northern Song forces captured the Northern Han capital of Taiyuan in present-day Shanxi Province after a two-month siege. A relief attempt by forces of the Liao dynasty, which was allied to the Northern Han, was easily defeated by the Northern Song. Yelü Dilie, a cousin of the Emperor Jingzong of Liao, was killed along with Yelü Sha's son Yelü Deli (è¶å¾Âå¾·è£Â).