The New People's Army was established on March 23, 1969, following the splinter of the Communist Party of the Philippines' Lava and Guerrero factions. Mistakes during the previous decades have led to the virtual dissolution of the PKP-1930 as an organization. The 1960s saw a resurgence in radical ideology, following the establishment of Kabataang Makabayan and the emerging popularity of Mao Tse Tsung Thought as an advancement of ideological Marxism-Leninism. In 1966, Jose Maria Sison, under the nom de guerre "Amado Guerrero", wrote "Rectify Errors and Rebuild the Party!", a treatise which criticized the old Lavaite leadership and emphasized the need to follow Mao Tse Tung Thought to foster re-establishment. The conflict continued until December 26, 1968, when the Communist Party of the Philippines was formally re-established along Maoist lines, and the entire issue was termed the First Great Rectification Movement.