渤海与新罗边疆接壤区域考

The Study on Contiguous Areas between Bohai and Xinluo

渤海定都东牟山后,向南收服“高丽和靺鞨余众”,势力范围迅速向南发展。新罗在占领百济故地后,势力范围向北推进。新罗军队应唐朝的要求,配合唐朝与渤海作战。战后,渤海与新罗在浿江下游流域(今大同江流域下游的平壤一带)和新罗东北的泥河一带形成两大接壤区域。为了巩固在边疆接壤区域的统治,新罗在浿江下游流域增设郡、县、军镇,向这一地区移民,渤海国则在南部地区设置南海府。但二者多数时间都只意图对边疆接壤地区进行治理,而非主动向对方发起军事进攻。原因在于渤海国在大钦茂即位后,国家侧重向北发展,对南部的经营以稳固为主;新罗则将更多的精力放在对百济故地的统治上,加之进入9世纪新罗内部斗争不断,限制了其向北发展;而此时的唐朝则通过册封双方国王等方式,与其建立良好关系,令其彼此相互牵制,以确保该区域的和平与稳定。

Bohai conquered the people of Gaogouli and Mohe,and expanded the territory southwards rapidly after the foundation of Bohai Kingdom.While Xinluo expanded their territory northwards after they have occupied Baiji.Xinluo's army,as the subordinated force of Tang Dynasty,has cooperated with Tang Dynasty to fight against Bohai.Gradually,it was forming two contiguous areas in the downstream of Bei River(today in the downstream of Taedong River,close to Pyongyang)and Ni River in Xinluo's northeast area between Bohai and Xinluo.In order to consolidate the rule in those two contiguous areas,Xinluo set up prefecture,county and army town,and immigrated people here;while Bohai set up the Nanhai Fu in south border area.However,Bohai and Xinluo attempted to control the contiguous areas respectively,but not to fight against each other.Since after Daqinmao succeeded to the throne,the expansion of Bohai Kingdom has focused on the northern area,and did not pay attention to the expansion southwards;it is limited northward expansion for Xinluo to pay more attention to govern the territory of Baiji,and Xinluo itself was troubled by internal struggle in 9th century;Tang's hegemony was maintaining a quite peaceful relationship with Bohai and Xinluo by granting official subordinated titles on their kingdom to keep them under mutual restraint and in a peace and stability in the contiguous areas.