The successor of the People's Revolutionary League of Rajia the CPR initially was banned by the Rajian government due to its radical communist teachings. During the rule of First Minister U Zaw Nyo the CPR became an underground movement. Following the start of the Rajian Campaign the organisation became a leading opposition movement to the regime of Zaw Nyo, eventually overthrowing his government in October 1945 creating a socialist republic in its place, sparking off the Rajian Civil War. In 1948 they reached a peace agreement with monarchist forces, but in 1978 royalists broke the ceasefire launching an offensive war that led to the collapse of East Rajia. This caused the party to go underground starting a people's war against the government.