高句丽与百济的军事对抗始于公元369年，至6世纪前叶，双方在一个半世纪的拉锯战中互有胜负。在双方实力处于相持不下的阶段，高句丽内部分化出意图向北发展的“征北派”和继续向南挤压百济的“征南派”。而从此后高句丽与南朝的朝贡疏离情况便能看出高句丽国内“征北派”和“征南派”的竞争情况。自安臧王以后，经历了安原王犹豫不决的对外观望，到阳原王由“征南派”变为“征北派”的反转，最后形成了平原王明确的以保持南部和平、重新将国家发展方向扭转向西北的重大国策转变，从此高句丽与百济结束了长达两个世纪的敌对状态，开始了逐步结盟、共同压制新罗的新阶段。
The military conflict between Goguryeo and Baekje started in 369 A.D.，which lasted for one and a half centuries，with a mixed record of victories and defeats on both sides.When they were roughly equal in the contest of strength，within Goguryeo there emerged a political division，one called “the North Expedition Camp” that intended to expand the empire northward，while the other “the South Expedition Camp” that argued for a continued effort to squeeze Baekje to its south.The increasingly distanced tributary exchange between Goguryeo and the Southern Dynasty was an indicator of the intensity of this factional struggle within Goguryeo.After the Anzang Emperor，there had been a series of policy changes within Goguryeo.The Anyuan Emperor held a hesitant attitude to merely observe the situation.When it came to the Yangyuan Emperor，there was a transition from the dominance of the “Southern Expedition Camp” to that of its Northern counterpart.Finally，during the Pingyuan Emperor's reign，there was a significant national policy reorientation，where the aim then was to maintain peace in the south and the expansion of the state was turned to its northwest.From this onwards，Goguryeo reached an end of bicentennial conflict with Baekje，starting a new period of gradual alliance and a concerted effort to pressure Xinluo.
