The Battle of Eastern Henan was between the Central Army of Chiang Kai-shek and those of Sun Dianying, a Henan native and ally of Feng Yuxiang and Yan Xishan. Sun's forces attacked the Longhai railway line, a stronghold on the eastern provincial border of Henan. The railway linked the cities of Kaifeng, Zhengzhou and Luoyang.
Fetching the article from Wikipedia…
Text from the Wikipedia article “Battle of Eastern Henan”, available under CC BY-SA 4.0.