After the Japanese surrendered on 15 August 1945, and the independence of Indonesia was proclaimed on 17 August 1945. The Indonesian government quickly set up provinces and appointed governors to the provinces. The Sumatra province, which consisted of the North Sumatra, Central Sumatra, and South Sumatra sub-province was formed, and Teuku Muhammad Hasan was inaugurated as the governor of the province on 29 September 1945. The North Sumatra sub-province consisted of Aceh, Tapanuli, and East Sumatra Residency.