Map Introduction

I. Establishment and Functions of the Liangzhe West Route

The Liangzhe West Route was first established in the 7th year of the Xining era (1074 AD) of the Northern Song and was formally confirmed as an independent administrative district in the 3rd year of the Jianyan era (1129 AD) after the Southern Song made Lin'an its capital. Its jurisdiction covered the northern part of modern Zhejiang and the southern part of Jiangsu, administering Lin'an Prefecture (the provisional capital), Pingjiang Prefecture (Suzhou), Zhenjiang Prefecture, Jiaxing Prefecture (Xiuzhou elevated in 1195 AD), Chang Prefecture, Hu Prefecture (renamed Anji Prefecture in 1225 AD), Yan Prefecture (elevated to Jiande Prefecture in 1265 AD), and Jiangyin Army, among others. As the political center of the Southern Song, the Liangzhe West Route performed the dual functions of the Fiscal Commission and the Pacification Commission. Lin'an Prefecture also served as the seat of the Zhexi Pacification Commissioner, who oversaw both military and civil affairs. Its administrative scope followed the Tang Dynasty tradition of dividing Eastern and Western Zhe by the Qiantang River. Geographically centered on the Hang-Jia-Hu Plain, it formed a three-tiered management system of "Superior Prefecture – Prefecture – Army".

II. Adjustments and Characteristics of the Liangzhe East Route

The Liangzhe East Route had its seat at Yue Prefecture (elevated to Shaoxing Prefecture in 1131 AD) and governed seven prefectures: Shaoxing, Wu, Qingyuan (Mingzhou elevated in 1195 AD), Rui'an (Wenzhou elevated in 1265 AD), Tai, Chu, and Qu Prefectures. After Yue Prefecture's elevation in the 1st year of the Shaoxing era (1131 AD), it became a secondary capital of the Southern Song, administering eight counties including Kuaiji and Shanyin, forming a tripartite administrative structure combining the "Grand Area Command – Kuaiji Commandery – Zhendong Army Military Governor". Qingyuan Prefecture (Ningbo), due to its elevated status in overseas trade, governed six counties including Yin and Fenghua, becoming the economic hub of Eastern Zhe. Bordered by the Qiantang River, the Liangzhe East and West Routes together formed the core fiscal region of the Southern Song, contributing over half of the nation's tax revenue.

III. Militarization of the Jiangnan East Route

The Jiangnan East Route (seat: Jiankang Prefecture) administered Jiangning Prefecture (Nanjing), Xuan Prefecture, Hui Prefecture, and others. In the 3rd year of the Jianyan era (1129 AD), Jiankang was elevated to a provisional capital, becoming the frontline against the Jin. Its administrative scope inherited that of the Northern Song's Jiangnan East Route, covering modern southern Anhui and the Nanjing area of Jiangsu. It strengthened its military defenses through the "Superior Prefecture – Prefecture – Army" system. After the 1141 Song-Jin peace agreement, Jiankang Prefecture, as the core of the Yangtze River defense line, saw its jurisdiction expanded with the addition of military strongpoints like Jiangyin Army, forming a defense network described as "using cities to anchor towns".

IV. Economic and Transport Linkages between the Three Routes

The Liangzhe West Route, centered on Lin'an, developed the nation's densest transportation network, with land and water main routes connecting prefectures, counties, and market towns, supporting the development of a commodity economy. The Liangzhe East Route, linked to overseas trade through the port of Qingyuan Prefecture, saw the formation of shipbuilding clusters in Wenzhou and Tai Prefectures. The Jiangnan East Route, leveraging the Yangtze River waterway, formed a material transport corridor with the Liangzhe West Route, making Jiankang Prefecture a hub for north-south trade. Together, these three routes constituted the Southern Song's "Jiang-Zhe Economic Sphere," laying the foundation for the later urban pattern of the Yangtze River Delta.