Question: How long had the place where the Jin court reestablished itself after fleeing been the capitol city of the headquarters location of Yaxing Coach?

Knowledge 1: Song dynasty
The Song dynasty is divided into two distinct periods, Northern and Southern. During the Northern Song (Chinese: 北宋; 960 -- 1127), the Song capital was in the northern city of Bianjing (now Kaifeng) and the dynasty controlled most of what is now Eastern China. The Southern Song (Chinese: 南宋; 1127 -- 1279) refers to the period after the Song lost control of its northern half to the Jurchen Jin dynasty in the Jin -- Song Wars. During this time, the Song court retreated south of the Yangtze and established its capital at Lin'an (now Hangzhou). Although the Song dynasty had lost control of the traditional ``birthplace of Chinese civilization ''along the Yellow River, the Song economy was still strong, as the Southern Song Empire contained a large population and productive agricultural land. The Southern Song dynasty considerably bolstered its naval strength to defend its waters and land borders and to conduct maritime missions abroad. To repel the Jin, and later the Mongols, the Song developed revolutionary new military technology augmented by the use of gunpowder. In 1234, the Jin dynasty was conquered by the Mongols, who took control of northern China, maintaining uneasy relations with the Southern Song. Möngke Khan, the fourth Great Khan of the Mongol Empire, died in 1259 while besieging the city of Chongqing. His younger brother Kublai Khan was proclaimed the new Great Khan, though his claim was only partially recognized by the Mongols in the west. In 1271, Kublai Khan was proclaimed the Emperor of China. After two decades of sporadic warfare, Kublai Khan's armies conquered the Song dynasty in 1279. The Mongol invasion led to a reunification under the Yuan dynasty (1271 -- 1368). [SEP] Knowledge 2: Zhejiang
At the beginning of the Three Kingdoms era (220–280 CE), Zhejiang was home to the warlords Yan Baihu and Wang Lang prior to their defeat by Sun Ce and Sun Quan, who eventually established the Kingdom of Wu. Despite the removal of their court from Kuaiji to Jianye (present-day Nanjing), they continued development of the region and benefitted from influxes of refugees fleeing the turmoil in northern China. Industrial kilns were established and trade reached as far as Manchuria and Funan (south Vietnam). [SEP] Knowledge 3: Yaxing Coach
Yaxing Coach (Yangzhou Yaxing Motor Coach Co., Ltd) is a bus manufacturer based in Yangzhou, Jiangsu, China. It is a subsidiary of Jiangsu Yaxing that was founded in 1998. Buses are produced under the "Yaxing", "Yangtse（Yangzlv）", and more recently Asiastar brands.
Knowledge 1: Yaxing Coach
Yaxing Coach (Yangzhou Yaxing Motor Coach Co., Ltd) is a bus manufacturer based in Yangzhou, Jiangsu, China. It is a subsidiary of Jiangsu Yaxing that was founded in 1998. Buses are produced under the "Yaxing", "Yangtse（Yangzlv）", and more recently Asiastar brands. [SEP] Knowledge 2: Song dynasty
The Song dynasty is divided into two distinct periods, Northern and Southern. During the Northern Song (Chinese: 北宋; 960 -- 1127), the Song capital was in the northern city of Bianjing (now Kaifeng) and the dynasty controlled most of what is now Eastern China. The Southern Song (Chinese: 南宋; 1127 -- 1279) refers to the period after the Song lost control of its northern half to the Jurchen Jin dynasty in the Jin -- Song Wars. During this time, the Song court retreated south of the Yangtze and established its capital at Lin'an (now Hangzhou). Although the Song dynasty had lost control of the traditional ``birthplace of Chinese civilization ''along the Yellow River, the Song economy was still strong, as the Southern Song Empire contained a large population and productive agricultural land. The Southern Song dynasty considerably bolstered its naval strength to defend its waters and land borders and to conduct maritime missions abroad. To repel the Jin, and later the Mongols, the Song developed revolutionary new military technology augmented by the use of gunpowder. In 1234, the Jin dynasty was conquered by the Mongols, who took control of northern China, maintaining uneasy relations with the Southern Song. Möngke Khan, the fourth Great Khan of the Mongol Empire, died in 1259 while besieging the city of Chongqing. His younger brother Kublai Khan was proclaimed the new Great Khan, though his claim was only partially recognized by the Mongols in the west. In 1271, Kublai Khan was proclaimed the Emperor of China. After two decades of sporadic warfare, Kublai Khan's armies conquered the Song dynasty in 1279. The Mongol invasion led to a reunification under the Yuan dynasty (1271 -- 1368). [SEP] Knowledge 3: Zhejiang
At the beginning of the Three Kingdoms era (220–280 CE), Zhejiang was home to the warlords Yan Baihu and Wang Lang prior to their defeat by Sun Ce and Sun Quan, who eventually established the Kingdom of Wu. Despite the removal of their court from Kuaiji to Jianye (present-day Nanjing), they continued development of the region and benefitted from influxes of refugees fleeing the turmoil in northern China. Industrial kilns were established and trade reached as far as Manchuria and Funan (south Vietnam).
Knowledge 1: Yaxing Coach
Yaxing Coach (Yangzhou Yaxing Motor Coach Co., Ltd) is a bus manufacturer based in Yangzhou, Jiangsu, China. It is a subsidiary of Jiangsu Yaxing that was founded in 1998. Buses are produced under the "Yaxing", "Yangtse（Yangzlv）", and more recently Asiastar brands. [SEP] Knowledge 2: Nanjing
Shortly after the unification of the region, the Western Jin dynasty collapsed. First the rebellions by eight Jin princes for the throne and later rebellions and invasion from Xiongnu and other nomadic peoples that destroyed the rule of the Jin dynasty in the north. In 317, remnants of the Jin court, as well as nobles and wealthy families, fled from the north to the south and reestablished the Jin court in Nanjing, which was then called Jiankang (建康), replacing Luoyang. It's the first time that the capital of the nation moved to southern part. [SEP] Knowledge 3: Zhejiang
At the beginning of the Three Kingdoms era (220–280 CE), Zhejiang was home to the warlords Yan Baihu and Wang Lang prior to their defeat by Sun Ce and Sun Quan, who eventually established the Kingdom of Wu. Despite the removal of their court from Kuaiji to Jianye (present-day Nanjing), they continued development of the region and benefitted from influxes of refugees fleeing the turmoil in northern China. Industrial kilns were established and trade reached as far as Manchuria and Funan (south Vietnam).

Answer: about 400 years