唐前期北衙的骑射部队——“北门长上”到“北门四军”的几点考察

Imperial Cavalry and Archery Troops of the Beiya in the Pre-Tang Days——Several Considerations on the “North gate Changshang Army” and the “Four North gate Forces”

唐代前期是北衙军力的初步形成阶段，北衙是在南衙的母体内孕育和发展起来的。北衙肇始于南衙诸卫轮番宿卫北门的旧有制度，但并非建立在与南衙对立的层面上，太宗至玄宗期间宫廷政变频生，加速了君主对精锐卫队的需求，北衙的建立从根本上改变着朝廷与宫廷的政治主导地位。

The imperial forces at the Beiya, which took an initial shape in the Pre Tang times, were generated and developed inside those at the Nanya. The Beiya forces were actually derived from the traditional system by wh ich the Nanya garrisons should be sent to guard the North Gate in turn, hence by no means a correspondent military arrangement to the Nanya. In addition, since the coup was so frequent between the reign of the Emperor Taizong and that of th e Emperor Xuanzong, the Sovereign’s demand was greatly intensified for the crac k garrisons. Therefore, the foundation of the Beiya forces gradually changed the dominating position of the imperial government to the court essentially.