A comrade of Lin Biao from their guerilla days, Chen was a commander of the New Fourth Army during the Sino-Japanese War (1937-1945), spearheaded the Shandong counter-offensive during the Chinese Civil War, and later commanded the Communist armies that defeated the KMT forces at Huai-Hai and conquered the lower Yangtze region in 1948-49. He was made a Marshal of the People's Liberation Army (PLA) in 1955.
After the founding of the People's Republic of China, Chen became mayor of Shanghai. He also served as vice premier from 1954 to 1972 and foreign minister from 1958 to 1972 and president of the China Foreign Affairs University from 1961 to 1969. During the Cultural Revolution, he was purged in 1967, but not officially dismissed, so Zhou Enlai performed the duties of foreign minister in his place.