北宋自雍熙三年北伐失败之后,对辽便由进攻转为全面防守。在迆逦千余里的边防前线,以步兵为主的宋军如何遏制住辽骑的奔轶,阻止其深入,从而固守住边陲,这是北宋君臣们必须首要考虑解决的问题。除了在缘边西部地区依仗太行山等天然险阻筑垒防守外,在河北平原地带修筑人工防御工程便被自然地提出并付诸实施。在这一工程中,就创制出了方田这一制式。这种所谓的方田,非后来神宗熙宁变法实施清查土地、整顿赋 After the defeat of the Northern Expedition by Emperor Yong of three years in North Song Dynasty, the Northern Song Dynasty shifted from an offensive to a full-scale defense. In front of the frontier defense in more than a thousand years, how did Song Jun, an infantry-based leader, stop Benjamin in Liao riding to prevent its in-depthness so as to hold the frontier? This is the issue that the Northern Song Dynasty monarchs must first consider. In addition to relying on natural hazards such as the Taihang Mountains in the western margin of the margin, it has naturally been proposed and implemented to build artificial defenses in the Hebei Plain. In this project, Fang Tian has created this system. This so-called Fang Tian, ​​non-Shenzong Xuning method of implementation of the inventory of land, rectify Fu