The birth of the Indonesian National Army is on the same date as the birth of TNI. On the 5th of October 1945 the Government of the Republic of Indonesia issued a decree about the founding of a national army named People's Security Army - formerly named People's Security Body.

People's Security Army had a mission to secure the state and people against armed disturbance from British soldiers and NICA- Netherlands Indies anvil Administration. At that time, with the Army as its core, People's Security Army had possessed other forces, namely the Navy, Air Force and Police. In addition, People's paramilitary units such as TRIP ( Student Army of the Republic of Indonesia) and TP (Student Army) and others, were founded as people's resistance organizations to safeguard the 1945 Indonesian independence.

Based on the Government Decree No. 2/SD dated 12 January 1946, People's Security Army was changed to People's Rescue Army with a mission to save the Republic of Indonesia with its people from being recolonized.

Next, on the 25th of January 1946 People's Security Army was changed to Indonesian People's Arm (TI) which consisted of Army, Navy and Air Force. On 5th May 1947 President of the Republic of Indonesia amalgamated the armed paramilitary units into

Indonesia People's Army and the Army was named TNI ADRI ( Army of the Republic oflndonesia). Later, it became the Armed Forces of the Republic of Indonesia (ABRI) in 1969, and on the 1st` April 1999 it was named as the Indonesian National Army ( TNI AD).

Based on the Presidential Decree No. 163/ 1999 dated 14 December 1999, the 15th of December is officially declared to be Hari Juang Kartika ( Day of struggle of he Army). On this date, the Indonesian National Army commemorates the great Battle of Ambarawa in 1945 and takes the unyielding battle spirits to be implemented in safeguarding the nation and country.