Explored the historical origin and evolution of the "Bengal route", pointing out that it was first mentioned by Feng Chengjun in "The History of Southeast Asian Transportation in China" and later explicitly proposed by Zhou Yunzhong. The route was part of the Ming Dynasty's Nanyang route, connecting China and Bangladesh. The article provides a detailed analysis of the five stages of airline development.

1、 Basic Stage

During the Han Dynasty to the Three Kingdoms period, maritime routes between China and South Asia were established, starting from Xuwen in Guangdong, Hepu in Guangxi, and Donghe City in Vietnam, and ending at Kangchipram in South India and Sri Lanka. During the Eastern Wu period, envoys and travelers such as Zhu Ying and Kangtai went to Southeast Asia for research and gained a preliminary understanding of the Bay of Bengal. During the Three Kingdoms period, some people may have been to the Henghekou area and were familiar with the local situation.

2、 Initial stage

A detailed discussion was conducted on the initial formation stage of the air route between China and Bangladesh from the Two Jin Dynasties to the Sui Dynasty (265-618 AD). During this period, although the route had been opened, multiple transfers were required to complete the journey from China to Bangladesh or vice versa. Faxian's return journey is a vivid example of the opening of the air route. He departed from the Tamali Emperor, passed through the country of Shizi and Yepati, and finally arrived at Laoshan Mountain in Qingdao, China. In addition, the maritime navigation experiences of Chinese monks such as Fayong and Zhiyan, as well as Indian monks such as Tanmoyashe and Fotuobatara, have also confirmed the existence of shipping routes. The experience of Qiunavarmo is particularly typical. He departed from Shizi Kingdom and traveled through Champa and Linyi to reach China, reflecting the complexity of the route and the necessity of transit at that time.

3、 Busy phase

The Tang, Song and Yuan Dynasties (618-1368) was the busy period of the ancient Bengal route. During this period, the merchants of the Maritime Silk Road included the Chinese, Indians, Persians, Romans and Arabs. The latter's participation significantly promoted the exchanges and trade between the East and the West. In the early Tang Dynasty, Yi Jing's "Biography of Eminent Monks Seeking Dharma in the Western Regions of the Great Tang Dynasty" recorded his departure from Guangzhou, passing through Shilifu (now Sumatra Island) and heading to Damoradi in East India. It detailed the routes and locations at that time, such as Tongzhu (now central Vietnam), Langjia (now Pattani, Thailand), Heling (now western Kalimantan Island), and Naked State (now Andaman Island, India). Yijing also recorded three small states in the Bengal region: Damoradi, Samadhi, and Khwarezmi, the latter located in the eastern part of present-day Bangladesh.

4、 Peak stage

In the early Ming Dynasty, Zheng He's seven voyages to the West strengthened the connection between China and Bangladesh, and related records increased. Zheng He's fleet departed from Jiangsu, passed through Southeast Asia, South Asia, the Persian Gulf, and the Red Sea, and finally arrived at the east coast of Africa. Books such as' Yingya Shenglan ',' Xingcha Shenglan ', and' Records of Western Barbarians' provide valuable materials for research. Hou Xian, as a eunuch in the Ming Dynasty, went on five diplomatic missions to foreign countries, including one visit to Bangladesh. Zhou Yunzhong proposed the concept of the "Bengal route" in "Zheng He's New Expedition to the West" and discovered new information, such as the record of Zhang Xuan's death in Jidagang, Bangladesh. It is speculated that the official factory established by the Ming Dynasty in Jidagang may have been in use until 1433.

5、 The Bangladesh route in the late Qing Dynasty

A detailed discussion was conducted on the history and importance of the Bangladesh route during the late Qing Dynasty. The investigation records of Huang Maocai reveal the trade connections between Myanmar's Rakhine State and Bangladesh, as well as the active presence of Chinese merchants in Chittagong. The records of Ma Jianzhong and Wu Guangpei provide information on the route from Tianjin to Hong Kong, and then to Kolkata, while pointing out that Penang Island is an important node on the route. Kang Youwei's travelogue emphasizes the convenience and safety of sea routes, as well as the frequent shipping from Guangdong to Kolkata at that time. Finally, the record of an Indian soldier shows the history of British military activities using the Bengal route from the mid-19th century to the early 20th century. These records collectively outline the commercial and military importance of the Bengal route in the late Qing Dynasty.