Complex sentence: Li Zongren, Bai Chongxi and Huang Shaohong of the Guangxi clique were the first to break off relations with Chiang in March 1929, which started the confrontation that lead to the Central Plains War, wherein Chiang Kai-shek defeated the clique in 1929.
Split into simpler sentences: Li Zongren, Bai Chongxi and Huang Shaohong of the Guangxi clique were the first to break off relations with Chiang in March 1929. This effectively started the confrontation which lead to the Central Plains War, wherein Chiang Kai-shek defeated the clique in 1929.