Editing Goguryeo (section)

====Goguryeo–Sui War====
{{Main|Goguryeo–Sui War|Battle of Salsu}}

The [[Sui dynasty]]'s reunification of China for the first time in centuries was met with alarm in Goguryeo, and [[Pyeongwon of Goguryeo]] began preparations for a future war by augmenting military provisions and training more troops.<ref>{{cite web |script-title=ko:평원왕[平原王, ? – 590] |url=https://www.doopedia.co.kr/doopedia/master/master.do?_method=view&MAS_IDX=181755}}</ref> Although Sui was far larger and stronger than Goguryeo, the Baekje-Silla Alliance that had driven Goguryeo from the Han Valley had fallen apart, and thus Goguryeo's southern border was secure. Initially, Goguryeo tried to appease Sui by offering tribute as Korean kingdoms had done under the [[Tributary system of China]]. However, Goguryeo continued insistence on an equal relationship with Sui, its reinstatement of the imperial title "Taewang" (Emperor in Korean) of the East and its continued raids into Sui territory greatly angered the Sui Court. Furthermore, Silla and Baekje, both under threat from Goguryeo, requested Sui assistance against Goguryeo as all three Korean kingdoms had desired to seize the others' territories to rule the peninsula, and attempted to curry Sui's favor to achieve these goals.

Goguryeo's expansion and its attempts to equalize the relationship conflicted with [[Sui dynasty|Sui China]] and increased tensions. In 598, Goguryeo made a preemptive attack on [[Liaoxi Province|Liaoxi]] which led to the [[Battle of Linyuguan]], but was beaten back by Sui forces.<ref>{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|publisher=Harvard University Press|isbn=978-0674615762|page=47|url={{GBurl|id=g2mdVwXpMzwC|p=47}}|access-date=16 November 2016|language=en|year=1984}}</ref> This caused [[Emperor Wen of Sui|Emperor Wen]] to launch a counterattack by land and sea that ended in disaster for Sui.<ref name="White">{{cite book|last1=White|first1=Matthew|title=Atrocities: The 100 Deadliest Episodes in Human History|publisher=W. W. Norton & Company|isbn=978-0393081923|pages=78–79|url={{GBurl|id=0-fQHlaIpR4C|p=78}}|access-date=16 November 2016|language=en|date=2011-11-07}}</ref>

Sui's most disastrous campaign against Goguryeo was in 612, in which Sui, according to the History of the Sui dynasty, mobilized 30 division armies, about 1,133,800 combat troops. Pinned along Goguryeo's line of fortifications on the [[Liao River]], a detachment of nine division armies, about 305,000 troops, bypassed the main defensive lines and headed towards the Goguryeo capital of Pyongyang to link up with Sui naval forces, who had reinforcements and supplies.

However, Goguryeo was able to defeat the Sui navy, thus when the Sui's nine division armies finally reached Pyongyang, they didn't have the supplies for a lengthy siege. Sui troops retreated, but General [[Ŭlchi Mundŏk]] led the Goguryeo troops to victory by luring the Sui into an ambush outside of Pyongyang. At the [[Battle of Salsu]], Goguryeo soldiers released water from a dam, which split the Sui army and cut off their escape route. Of the original 305,000 soldiers of Sui's nine division armies, it is said that only 2,700 escaped to Sui China.

The 613 and 614 campaigns were aborted after launch—the 613 campaign was terminated when the Sui general [[Yang Xuangan]] rebelled against [[Emperor Yang of Sui|Emperor Yang]], while the 614 campaign was terminated after Goguryeo offered a truce and returned Husi Zheng (斛斯政), a defecting Sui general who had fled to Goguryeo, Emperor Yang later had Husi executed. Emperor Yang planned another attack on Goguryeo in 615, but due to Sui's deteroriating internal state he was never able to launch it. Sui was weakened due to rebellions against Emperor Yang's rule and his failed attempts to conquer Goguryeo. They could not attack further because the provinces in the Sui heartland would not send logistical support.

Emperor Yang's disastrous defeats in Korea greatly contributed to the collapse of the Sui dynasty.<ref name="White" /><ref>{{cite book|last1=Bedeski|first1=Robert|title=Human Security and the Chinese State: Historical Transformations and the Modern Quest for Sovereignty|publisher=Routledge|isbn=978-1134125975|page=90|url={{GBurl|id=iNl9AgAAQBAJ|p=90}}|access-date=16 November 2016|language=en|date=2007}}</ref><ref>{{cite book|last1=Ebrey|first1=Patricia Buckley|last2=Walthall|first2=Anne|last3=Palais|first3=James B.|title=East Asia: A Cultural, Social, and Political History, Volume I: To 1800|publisher=Cengage Learning|isbn=978-1111808150|page=106|url={{GBurl|id=CWE8AAAAQBAJ|p=106}}|access-date=16 November 2016|language=en|year=2013}}</ref>