Map Introduction

Yan Province * Geographical Scope: Roughly covering modern western Shandong and eastern Henan provinces. Its administrative seat was at Changyi (modern Dingtao District, Heze City). * Administrative History: During the Eastern Han Dynasty, Yan Province administered eight commanderies and principalities. The Cao Wei regime of the Three Kingdoms period retained this structure, only changing Chenliu Commandery to the Chenliu Principality and Rencheng Commandery to the Rencheng Principality. * Key Events: Cao Cao temporarily controlled Yan Province, consolidating his rule by suppressing rebellions, confiscating lands from powerful local families, and implementing the agricultural garrison (tuntian) system. However, the province was briefly lost following an invasion by Lü Bu.

Yu Province * Geographical Scope: Encompassing modern central-eastern Henan and northern Anhui provinces. Its administrative seat was at Runan (modern Runan County, Zhumadian City). * Administrative History: In the Eastern Han, Yu Province governed six commanderies and principalities. Cao Wei continued this administrative framework during the Three Kingdoms period and strengthened its control over this core Central Plains region. * Economic Significance: As a major grain-producing area, Yu Province was a long-term, strategic source of military provisions for the Wei state.

Yang Province * Geographical Scope: Included parts of modern Anhui, Jiangsu, and Jiangxi provinces. Its administrative seat was at Shouchun (modern Shou County, Huainan City). * Administrative History: The Eastern Han Yang Province consisted of six commanderies. While Cao Wei brought it under its nominal dominion during the Three Kingdoms period, its actual control was weak, and local powers retained significant autonomy. * Cultural Influence: The Yangzhou region produced numerous notable figures. Prominent Eastern Wu generals like Zhou Yu and Lu Xun were active here.

Regional Interrelations

These three provinces were all part of Cao Wei's core territory. However, due to their geographical dispersion, regional separatism frequently occurred in Yu and Yang Provinces. For instance, Yu Province witnessed the rebellion of Zhang Miao, while Yang Province saw continued activity by remnants of Eastern Wu forces.