In the week following the Japanese surrender, the Giyugun (PETA) and Heiho groups were disbanded by the Japanese. Command structures and membership vital for a national army were consequently dismantled. Thus, rather than being formed from a trained, armed, and organised army, the Republican armed forces began to grow in September from usually younger, less trained groups built around charismatic leaders. Creating a rational military structure that was obedient to central authority from such disorganisation, was one of the major problems of the revolution, a problem that remains through to contemporary times. In the self-created Indonesian army, Japanese-trained Indonesian officers prevailed over those trained by the Dutch. A thirty-year-old former school teacher, Sudirman, was elected 'commander-in-chief' at the first meeting of Division Commanders in Yogyakarta on 12 November 1945.