Yuan Shikai and Sun Yatsen had a falling out which eventually lead to the dissolution of parliament and Yuan Shikai attempting to install a modernized monarchy with himself as the emperor. Why did this happen? Because the glue holding the Beiyang clique and the Revolutionary party together, Song Jiaoren was assassinated. Just about everyone living at the time of the assassination believed it to be an attempt at power grab by Yuan Shikai. But modern evidence, and confessions by descendants of both Yuan Shikai and Revolutionary Party memebers points to that Yuan Shikai was framed. The assassination of Song Jiaoren was staged by the Revolutionary Party in order to frame Yuan Shikai and the Beiyang clique.

For what reason? To topple the military-based Beiyang clique and install the intellectual-based Revolutionary Party as the governing party of the Chinese government. After the Xinhai revolution, China was in a great state. It is one of the few civil wars with minimal casualties possible in Chinese history. A civil parliamentary republican government was established and Yuan Shikai the newly sworn in president was a capable governor. This honeymoon period didn't last too long however, communication problems between the Revolutionary Party and the Beiyang clique ended in Sun Yatsen declaring a second revolution after the assassination of Song Jiaoren. The government devolving into a state of chaos led to Yuan Shikai attempting to centralize the government through monarchism. This backfired on Yuan Shikai when several generals renounced their association with Yuan Shikai for attempting to undo the republican government, they rebelled against Yuan Shikai and declared autonomy over the provinces their army was stationed in. Yuan Shikai's death led to furthur decentralization of power, many generals formerly loyal to Yuan Shikai also broke off and declared autonomy over their respective provinces. Thus began one of the most catastrophic periods in modern Chinese history: the Warlord Era.