In 1873, the Imperial government asked the newly appointed War Minister to organize a national army for Japan. So Yamagata convinced the government and enacted a conscription law in 1873 which established the new Imperial Japanese Army. The law established military service for males of all classes, for a duration of 3 years, with an additional 4 years in the reserve. Yamagata modernized and modeled it after the Prussian Army. Duke Yamagata Aritomo was born in a lower ranked samurai family from Hagi. He was a field marshal in the Imperial Japanese Army and twice Prime Minister of Japan. He was one of the main architects of the military and political foundations of early modern Japan. Yamagata Aritomo is regarded as the father of Japanese militarism.