After a period of slow growth and the First United Front with the Kuomintang (Chinese Nationalist Party), the alliance broke down and the Communists fell victim in 1927 to a purge carried out by the Kuomintang under the leadership of Chiang Kai-shek. After 1927, the Communists retreated to the countryside and built up local bases, such as the Jiangxi Soviet, which it held until Nationalist pressure forced the Long March. During the Japanese invasion and occupation, the Communists built more secret bases in the Japanese occupied zones and relied on them as headquarters.