In 1851, after leaving the Royal Military College, Austen was commissioned into the 24th Foot, which later became the South Wales Borderers. In 1852 he saw action in the Second Anglo-Burmese war, in which he served as aide-de-camp to his grandfather, General Sir Henry Godwin. While in Burma, he surveyed the Irrawaddy Delta, and this work came to the favourable notice of Sir Andrew Scott Waugh, Surveyor General of India. Austen next moved to Peshawar under the command of Major General Thomas Reed. His maternal grandfather died unexpectedly in 1853, and as a result Robert Austen added the name of Godwin to his own, so that Austen became Godwin-Austen.