우문술
Despite this, Emperor Yang launched his first campaign against Goguryeo in 612, crossing the Liao River into Goguryeo territory in spring 612. Emperor Yang personally led part of the army to put the important city Liaodong (遼東, in modern Liaoyang, Liaoning) under siege, while he sent the Xianbei generals Yuwen Shu and Yu Zhongwen (于仲文) to lead the rest of the army deep into Goguryeo territory, heading toward the Goguryeo capital Pyongyang, joined by the fleet commanded by the southern Chinese general Lai Hu'er. Emperor Yang, however, was never able to capture Liaodong, while Yuwen and Yu, advancing nearly to Pyongyang, were defeated by the Goguryeo general Eulji Mundeok and forced to withdraw with heavy losses. By fall 612, Emperor Yang was forced to terminate the campaign and withdraw as well, with only minor territorial gains. About 300,000 men had been lost in the campaign.