The City Wall Structure and the Drivers of Change in the Capital Cities of China’s Eastern Zhou Period

This paper examines the transitional phase in ancient Chinese urban planning by analyzing the structural characteristics and changes in the city wall systems of capital cities during the Eastern Zhou Period (東周時代). Firstly, this study defines the terms “inner city wall” (城) and “outer enclosure” (郭) based on historical texts, distinguishing their conceptual and structural differences. Subsequently, the structural typologies of city walls in the Eastern Zhou Period are classified through archaeological cases into three categories: “no city wall or enclosure” (無城無郭), “city wall without enclosure” (有城無郭), and “city wall with enclosure” (有城有郭). Additionally, the research confirms that while Eastern Zhou city wall structures inherited the typical Western Zhou Period (西周時代) inner-city and outer-enclosure system (內城外郭), by the Warring States Period (戰國時代), diverse forms such as “parallel city walls and enclosures” (城郭竝立) and “separated city walls and enclosures” (城郭分離) emerged according to the political and institutional contexts of various states. These structural transformations were closely linked to the reorganization of hierarchical spatial structures, stabilization of political authority, and strategic shifts in capital defense. The Eastern Zhou era was characterized by the collapse of the traditional Zhou clan-based hierarchical order (宗法的), alongside intensifying military conflicts among feudal states, demanding fundamental changes in urban governance and defense strategies. Consequently, feudal states transitioned from the traditional inner-city and outer-enclosure model toward more varied forms like parallel or separated city wall systems. By analyzing the evolution of city wall structures in the Eastern Zhou capitals, this research contributes to understanding the historical transformations of ancient Chinese urban structures and also provides significant comparative data for studies on ancient Korean capital cities.