King p’y?ngw?n’s ascension to the throne during the late 6th century coincided with Kogury?’s overcoming of the crisis it had experienced in terms of its power during the mid-6th century via the strengthening of its royal authority and settling of public sentiment. Thereafter, during the reign of King Y?ngyang, Kogury? attacked Silla. While this first attempt is best remembered for marking the rise of Ondal, who had first been appointed during the reign of King p’y?ngw?n, as a new power figure, this attempt ultimately ended in failure. Kogury? subsequently attacked Liaoshi in 598 however, this campaign also failed amidst a counterattack on the part of the Sui(隋) dynasty. Having led the campaign against Liaoshi. King Y?ngyang found himself in a precarious political position following its failure. However, he was able to overcome these difficulties by initiating a second round of attacks on Silla in 603. In 608, King Y?ngyang was able to achieve some victories on the battlefield against Silla.
However, King Y?ngyang’s policy came under both domestic and international pressure following the Sui dynasty’s decision to dispatch a second expedition to Kogury? in 612. On thedomestic front, strong resistance emerged amongst the aristocrats to the attempts to further invigorate the royal authority. The strong dependence of the figures appointed and actively engaged in politics during the reigns of King P’y?ngw?n and Y?ngyang on royal authority meant that their political power vis-a-vis the aristocrats was quite limited. On the other hand, the campaign against Silla facilitated Silla’s overture tothe Sui dynasty and in essence caused the latter’s expedition to Kogury?. The combined forces of Silla and Sui were able to wrest some 500-ri of territory from Kogury?. This denouement was the result of the weakening of the ability to resist against external shock occasioned by the stretching of its front line defense to the breaking point amidst a two-pronged attack by Sui and Silla.
As such, although King Y?ngyang made efforts to continue the policy course set by King P’y?ngw?n and strengthen the royal authority, his efforts were frustratedby a limited understanding of the political situation at the time. His attack on Silla implemented as part of this policy also ended in failure because of the Sui dynasty’s invasion of Kogury?. These results greatly influenced his attempts to strengthen the royal authority.