Please introduce in detail the area referred to by "Jiangnan" from pre-Qin to modern times (it is best to indicate the reference materials).

There was a saying of Jiangnan in the pre-Qin period. Until the Sui Dynasty, the Central Plains was still the center of geographical coordinates, and Jiangnan often referred to the area south of the Yangtze River in Hunan and Hubei.

Jiangnan Road was established in the Tang Dynasty, and later it was divided into Jiangnan East Road, Jiangnan West Road and Guizhou Middle Road, which became the beginning of defining the meaning of modern Jiangnan, and later Jiangnan became the proper name of Jiangdong area. The evolution of administrative divisions named after "Jiangnan" in history;

* Before the Tang Dynasty, the term Jiangnan included the vast areas along the Yangtze River, including Jingzhou (southeastern Hubei and Hunan) and Yangzhou (Jiangxi, southern Anhui, Fujian, southern Jiangsu, Shanghai and Zhejiang).

* Jiangnan West Road (southeastern Hubei, Hunan, Jiangxi and southern Anhui) and Jiangnan East Road (Fujian, southern Jiangsu, Shanghai and Zhejiang) were established in the Tang Dynasty.

* Jiangnan West Road (most of Jiangxi, southeastern Hubei) and Jiangnan East Road (northeastern Jiangxi, southern Anhui and Nanjing) were established in the Song Dynasty.

* In the early Qing Dynasty, 1645 established jiangnan province, and 1667 divided Jiangsu Province and Anhui Province. However, jiangnan province includes not only parts of the south of the Yangtze River, but also a large area north of the Yangtze River (Huaibei and Subei).

Emperor Taizong established Jiangnan Road, covering the whole middle and lower reaches of the Yangtze River, south of the Yangtze River and Guizhou and Fujian. Tang Xuanzong subdivided Jiangnan Road into Jiangnan East Road, Jiangnan West Road and Qianzhong Road. Jiangnan was divided into eastern Jiangnan and western Jiangnan in ancient times. Jiangnan West Road and Jiangnan West Road were established in the Tang and Song Dynasties, covering Jiangxi, Hunan and southern Hubei in the west of the Yangtze River, and originally belonged to Jiangnan in a broad sense. Later, with the narrow concept of Jiangnan, Jiangnan West Road evolved into today's Jiangxi Province; Jiangdong area is centered on Nanjing, mainly including parts of Jiangsu, Zhejiang and Anhui. In the Qing Dynasty, the Governor's Office of Two Rivers was established, which governed Jiangsu Province (including Shanghai), Anhui Province and Jiangxi Province, and the two rivers included Jiangdong and Jiangxi.

Modern Jiangnan

The definition of modern Jiangnan can be divided into two types: broad Jiangnan and narrow Jiangnan.

Jiangnan in a broad sense refers to the whole Jiangnan area in the middle and lower reaches of the Yangtze River, namely, southern Jiangsu, southern Zhejiang, southern Anhui, southern Jiangxi, southern Hunan and southern Hubei. Some areas in Fujian are sometimes called Jiangnan. The broad definition of Jiangnan begins with Gusi (Jiangnan Road) and is often described in literary works. For example, Du Fu's Random Encounter Li Guinian was written in Changsha. The Jiangnan referred to in the weather forecast is roughly the Jiangnan zone in a broad sense. Three famous buildings in the south of the Yangtze River (Yellow Crane Tower in Wuhan, Yueyang Tower in Yueyang and Wangtengting Pavilion in Nanchang) are all located in the south of the Yangtze River.

Jiangnan in a narrow sense generally refers to southern Jiangsu and northern Zhejiang, but the specific scope is not very clear. This concept probably began in the late Tang Dynasty and took shape in the Ming and Qing Dynasties. The clearest core area in Jiangnan only includes Suzhou, Hangzhou, Wuxi, Changzhou and other cities around Taihu Lake. Nanjing is also located in the core area of the south of the Yangtze River. However, due to the changes of the times, the language of Nanjing has gradually become Jianghuai Mandarin (Jiangbei dialect), so the recognition of Nanjing in Wuyu District is not high. Shanghai's administrative history is relatively short, but because of its important economic status, it has basically been included in the modern concept of "Little Jiangnan".

However, it is not the Yangtze River basin, and it is considered to be some areas south of Taihu Lake or even south of Qiantang River, such as Shaoxing and Ningbo. Some areas north of the lower reaches of the Yangtze River, such as Yangzhou, are located in the north of the Yangtze River, but their economy and culture are similar to those of Jiangnan, and sometimes they are regarded as a part of Jiangnan in the cultural sense. Similarly, because of Jiangbei dialect, the narrow sense of Jiangnan does not necessarily include Yangzhou and Zhenjiang.

Not only Jiangnan in a narrow sense, but also Jiangnan in a broad sense often appears and praises in the description of historical documents. For example, the three famous buildings in the south of the Yangtze River all have the poet's famous sentences "Yueyang Tower" and "Wang Tengting Preface", so it is uncertain when the narrow definition of the south of the Yangtze River was formed, and it can only be proved that it gradually evolved at the end of the Tang Dynasty.