 In 598, Goguryeo made a preemptive attack on Liaoxi, leading Emperor Wen to launch a counterattack by land and sea that ended in disaster for Sui.In 612, Emperor Yang mobilized a huge force said to number over a million men and invaded Goguryeo.Unable to overcome the defenses of Yodong (Liaodong) Fortress, Emperor Yang ordered 305,000 troops to attack the Goguryeo capital of Pyongyang.