During the Second Dutch Military Aggression, the Emergency Government of the Republic of Indonesia was formed in Sumatra, in which A.K. Gani became military governor and Maludin Simbolon became the deputy. In 1950, he was appointed commander of the Bukit Barisan Territorial-I Army Command, which was formed in conjunction with the formation of the North Sumatra Province which included Aceh, North Tapanuli, South Tapanuli, West Sumatra, and East Sumatra.