Qinling–Huaihe Line in the context of "Qinling"

The Jin dynasty (/dʒɪn/, Chinese: 金朝; pinyin: Jīn cháo), officially the Great Jin (大金; Dà Jīn), was a Jurchen-led imperial dynasty of China and empire ruled by the Wanyan clan that existed between 1115 and 1234. It is also often called the Jurchen dynasty or the Jurchen Jin after the ruling Jurchen people. At its peak, the empire extended from Outer Manchuria in the north to the Qinling–Huaihe Line in the south.

The Jin dynasty emerged from Wanyan Aguda's rebellion against the Liao dynasty (916–1125), which held sway over northern China until being driven by the nascent Jin to the Western Regions, where they would become known in Chinese historiography as the Western Liao. After conquering the Liao territory, the Jin launched a century-long campaign against the Song dynasty (960–1279) based in southern China, whose rulers were ethnically Han Chinese. Over the course of the Jin's rule, their emperors adapted to Han customs and even fortified the Great Wall against the ascendant Mongol Empire. The Jin also oversaw a number of internal cultural advances, such as the revival of Confucianism.

North China (Chinese: 华北) is a geographical region of the People's Republic of China, consisting of five provincial-level administrative divisions, namely the direct-administered municipalities Beijing and Tianjin, the provinces Hebei and Shanxi, and the autonomous region Inner Mongolia (although the four prefectures east of the Greater Khingan Range are sometimes regarded as parts of Northeast China).

Part of the larger region of Northern China (Beifang), it lies north of the Qinling–Huaihe Line, with its heartland in the North China Plain. Most inhabitants here speak variants of Northern Chinese languages such as Mandarin, which includes the Beijing dialect and its cousin variants. The Beijing dialect is largely the basis of Standard Chinese (or Standard Mandarin), the official language of the People's Republic of China. Jin Chinese and Mongolian are also widely spoken due to the political and cultural history of the area.

The Huai River, formerly romanized as the Hwai, is a major river in East China, about 1,110 km (690 mi) long with a drainage area of 174,000 km (67,000 sq mi). It is located about midway between the Yellow River and Yangtze River, the two longest rivers and largest drainage basins in China. Historically draining eastwards directly into the Yellow Sea, erosion from floods have changed the course of the river such that it now primarily discharges into the Yangtze. The Huai River is, to this day, notoriously vulnerable to flooding.

The Qinling–Huaihe Line, formed by the Huai River and the Qin Mountains, is sometimes regarded as the geographical dividing line between northern and southern China. This line approximates the 0 °C (32 °F) January isotherm and the 800 millimeters (30 in) isohyet in China.

The Heihe–Tengchong Line (simplified Chinese: 黑河–腾冲线; traditional Chinese: 黑河–騰衝線; pinyin: Hēihé–Téngchōng xiàn), also called the Aihui–Tengchong Line (and internationally as the Hu line), is a line that divides the area of China into two parts with contrasting population densities. It stretches from the city of Heihe in the northeast to Tengchong in the south, diagonally across China. The eastern portion, area shown in red in the map, is further subdivided into north and south halves.

As of 2015, 43% of the Chinese territory is east of the line and has 94% of the country's population, and 57% of the Chinese territory is west of the line and has only 6% of the country's population.