In 1941, the New Fourth Army sent its Third, Fourth, and Fifth Detachments from Pudong, Shanghai, across the sea to the Siming Mountains in Yuyao, Zhejiang, to fight the Japanese. Led by Tan Zhenlin, the Third and Fifth Detachments established an anti-Japanese base in eastern Zhejiang, opening up a new front for the New Fourth Army's resistance south of the Yangtze.
