brought increased tensions within the United Front as Chiang Kai-shek began to consolidate power in preparation for the Northern Expedition. The former leaders of the Paris anarchist group Zhang Renjie, Li Shizeng, Wu Zhihui and Cai Yuanpei had become known as the Four Elders of the Kuomintang, holding strong influence over the party and supporting Chiang Kai-shek's candidacy for the leadership. The Four Elders took a hardline stance against the communists as well as the left-wing of the KMT, who perceived their activities as threatening an anarchist takeover of the party. Division of the United Front On 20 March 1926, Chiang Kai-shek launched the Canton Coup, purging hardline communists who opposed the proposed Northern Expedition. In an attempt to balance the need for communist assistance with his concerns about growing communist influence, After Zhang Renjie counseled Chiang against identifying himself too closely with the right, Chiang negotiated the removal of hardline members of the KMT's right-wing faction from their posts in compensation for the purged leftists. Soviet aid to the KMT government continued, as did co-operation with the CCP, holding together the United Front long enough to lay the groundwork for the Northern Expedition. The first phase of the expedition began in July 1926, capturing the provinces of Hunan, Hubei and Henan from the forces of Wu Peifu, and the provinces of Fujian, Jiangxi, Zhejiang, Anhui and Jiangsu from the forces of Sun Chuanfang, eliminating the Zhili clique in the process. The headquarters of the nationalist government subsequently moved from Guangzhou to Wuhan, while Communist-led trade unions began establishing parallel structures in the areas that had been captured by the National Revolutionary Army. Independent peasant rebels also began to take control of large swaths of land and started to govern themselves, which in response alienated much of the KMT's military leadership, who were generally opposed to peasant self-rule. The Wuhan government, which was controlled by Wang Jingwei's leftist faction of the KMT, aided by the CCP, as well as widespread grassroots support, transformed Wuhan into "a seedbed for revolution", while portraying themselves as the sole legitimate leadership of the KMT. Controlling much of Hunan, Hubei, Guangdong and Jiangxi, the Wuhan government began challenging Chiang's authority, nominally stripping him of much of his military authority, though refrained from deposing him as commander-in-chief. The CCP also became an equal partner in the Wuhan government, sharing power with the KMT leftists. In response