釋氏稽古略 4.36

4.36

乙亥開寶八年　遼乾亨二年　三月往聘宋。宋乃初通使於遼。

Yihai, eighth year of Kaibao; Liao, second year of Qianheng. In the third month, [envoys] went to pay respects to the Song; the Song then began diplomatic communication with the Liao for the first time.