井冈山
Zhu's close affiliation with Mao Zedong began in 1928 when, with the help of Chen Yi and Lin Biao, Zhu defected from Fan Shisheng's protection and marched his army of 10,000 men to Jiangxi and the Jinggang Mountains. Here Mao had formed a soviet in 1927, and Zhu began building up his army into the Red Army, consolidating and expanding the Soviet areas of control. The meeting, which happened on the Longjiang Bridge on April 28, 1928, was facilitated by Mao Zetan, who was Mao's brother serving under Zhu. He carried a letter to his brother Mao Zedong where Zhu stated, "We must unite forces and carry out a well-defined military and agrarian policy." This development became a turning point, with the merged forces forming the "Fourth Red Army", with Zhu as Military Commander and Mao as Party representative.