Asia Pacific 1930: Central Plains War
Treaty ports were towns opened to foreign trade by unequal treaties in China. Foreigners operating within treaty ports enjoyed extraterritoriality, being subject to their home country’s laws. Unlike concessions such as Hong Kong, these territories were not directly leased by the foreign powers and did not have sizable foreign garrisons.
Treaty ports are not shown in the maps after the 1911 Chinese Revolution in order to give a clearer picture of the chaos in China itself and as by that point their numbers had stabilized. After the revolution, some of the smaller ports were phased out while the others became less important as the situation in China meant that only the concessions could provide foreigners with security. Most, however, still continued on into the 1940s when the Japanese entry into World War II and foreign agreements with China brought them to an end.
See this map for treaty ports in 1907, when the system was at its peak.
By the terms of the Treaty of Tientsin (1858), foreign vessels including warships had the right to free navigation on the Yangtze River. In practical terms, this right extended only as far as Yichang until 1900, when advances in steam navigation allowed access as far inland as Chongqing.
22 Dec 1929 KMT accept peace with USSR▲
The Khabarovsk Protocol ended the Sino-Soviet Conflict and restored joint Soviet-Chinese administration of the Chinese Eastern Railway.
Feb 1930 Yan Xishan denounces Chiang Kaishek▲
Yan Xishan denounces Chiang Kaishek
1 Apr 1930 Yan Xishan expels Chiang Kaishek's men from Tianjin and Beiping▲
Yan Xishan expels Chiang Kaishek's men from Tianjin and Beiping
May 1930 Outbreak of Central Plains War▲
Chiang Kaishek and his allies vs Yan Xishan, Feng Yuxiang and the Guangxi clique