Robert Milligan joined the army on September 2, 1956 aged 19. he graduated from Officer Cadet School Portsea 'Dux' of his class. He served as a lieutenant with the Pacific Islands Regiment, Papua New Guinea.
Captain Milligan was 2nd in command of C Company when on the morning of February 14 1967, during a search of Xa An Nhut village, a mine exploded killing Captain Milligan, Major Bourne and Captain Williams.

Official Commemoration: NSW - Macquarie Park Cemetery
Commemoration Position: General Lawn - Row 17 - Grave 54