In spring 645, Li Shiji reached You Prefecture (, roughly modern Beijing), and then headed into Goguryeo territory. Together with Li Daozong, he captured Gaemo (, in modern Fushun, Liaoning), and then put the important city of Liaodong/Yodong (, in modern Liaoyang, Liaoning) under siege.
In spring 645, Li Shiji's military campaign led him to You Prefecture (now Beijing) and subsequently into Goguryeo territory. Alongside Li Daozong, he successfully captured Gaemo (now Fushun, Liaoning), and then besieged the key city of Liaodong/Yodong (now Liaoyang, Liaoning).